Children’s Functional Clothing: Design Challenges and Opportunities

Abstract

Functional textiles and clothing designed for children should provide a safe and supportive environment, encompassing comfort, safety, health, wellbeing, and cognitive development, as well as fostering interaction and exploration. This study explores the multifaceted nature of functional textiles and clothing for children. It emphasises the importance of comprehensive knowledge about the user and an interdisciplinary approach in the design process. The integration of expertise from diverse fields contributes to a holistic understanding of the challenges and opportunities inherent in creating clothing that satisfies aesthetic demands and promotes the wellbeing of children. Through a study of existing research in functional textiles and a market analysis of children’s clothing, this research underscores the importance of practical application of studied materials and technologies in children’s fashion, creating innovative and purposeful solutions. This collaborative effort involves working with multidisciplinary teams and applying designers’ updated knowledge of functional materials throughout all stages of the design process. The study emphasises the designer’s responsibility in articulating the essential knowledge needed to integrate functionality from the beginning of the design process, ensuring that practical considerations are integral to the core attributes of the clothing. The study also proposes a framework that represents the design process for functional children’s clothing.

1. Introduction

Designers have many challenges. In an era where sustainability is paramount, they must navigate a complex landscape of eco-conscious materials and production methods. However, the search for sustainability is not an isolated challenge. Climate change and pollution have precipitated a global health crisis, with an increasing number of diseases attributed to their effects [1].

Consumers are displaying a growing preoccupation with hygiene, cleanliness and protection. These concerns are specifically pertinent in the context of children’s clothing. Due to their vulnerable nature, children are more prone to infections and skin sensitivities that can be positively or negatively affected by textiles [2,3]. Furthermore, addressing the needs and aspirations of minority segments in the market represents a unique challenge that arises from the inherent diversity of society. It is recognised that individuals belonging to these segments may have different experiences, perspectives and needs.

Considering the increasing significance that consumers attribute to health and wellbeing, the concept of functional clothing design has started to gain attention, although it still requires extensive research. This approach to garment creation transcends aesthetics and basic safety considerations, prioritising the ability of clothing to serve multiple purposes, thereby increasing its overall utility [4].

A study by Shaharuddion and Jalil [5] found that there is a high acceptance of functional clothing among consumers, but there is little supply in the children’s market. This can be corroborated by the assertion made by Jalil and Shaari [6], which states that functional fashion design is presently not a subject of research, especially functional children’s fashion design. Designing functional clothing for children presents a distinctive challenge that demands a thorough grasp of multiple disciplines. The limited study of this topic in the literature may be attributed to the vulnerability of children, resulting in more stringent laws and regulations regarding the safety standards for introducing clothing items into the market [7]. Moreover, the need to consolidate expertise from diverse fields and participate in collaborative efforts is a significant challenge to overcome in order to improve the creation of clothing that complies with safety regulations and also improves the comfort and general wellbeing of children.

This work delves into the urgent requirement for designers to possess a thorough understanding of sustainable and functional materials, technologies, and practices right from the inception of the design process.

2. Methodology

The literature review adopted a qualitative analysis methodology. A thorough and critical examination of research articles, reviews, and book chapters was carried out in order to understand the challenges and opportunities inherent in creating clothing that not only satisfies aesthetic demands but also promotes the wellbeing of children. Initially, keywords such as “design process”, “design interdisciplinarity”, “functional textiles”, “functional clothing”, and “children’s clothing” were identified as the basis for the literature search. These keywords were then used to search in prominent academic databases, including Scopus and Web of Science. Additionally, the snowball sampling method [8] was employed to broaden the search scope through the analysis of references cited in articles or book chapters initially collected.

Following the database search, an open search was conducted to identify brands and products focusing on children’s functional day-to-day clothing, encompassing both online platforms and information from articles and websites associated with other brands. Four research indicators (target, functionalities, textile materials and technologies) were developed to evaluate the functionalities of children’s clothing products and identify the predominant technologies used in this market. Concurrently, an in-depth exploration of the designer’s role in creating children’s functional clothing was undertaken. This included an analysis that interconnects the thematic areas studied to elucidate the designer’s responsibilities and main considerations during the design process of functional children’s clothing.

3. The Design Process of Functional Children’s Clothing

Design is a problem-solving discipline that centres around creating solutions that establish harmonious relationships between products and their intended contexts, aiming to realise user satisfaction [9,10]. This systematic and thoughtful approach involves identifying, analysing, and addressing challenges throughout the design process, resulting in solutions that resonate with the needs and desires of end user [10].

Consumers are increasingly attracted to clothing that not only looks good but also offers functional properties that safeguard the child’s health and wellbeing [11]. Acknowledging the importance of practical functions in children’s clothing is essential in this context. However, it is equally necessary to ensure that functional clothing has aesthetic qualities that align with the wearer’s visual preferences. Functional children’s fashion design is an emerging field dedicated to creating clothing for children that achieves a harmonious balance between aesthetics and functionality.

According to Kariuki [12], high-quality clothing is characterised by a professional appearance, a well-fitted design, durability, ease of maintenance, and a non-hazardous impact on the user. Additionally, as posited by Cunha and Broega [10], functional fashion garments are designed to provide versatile utility across various scenarios. They adapt to diverse situations or weather conditions, and they can present distinct characteristics in various body areas by incorporating different functional features. This progressive approach aims to improve the versatility and utility of children’s clothing, achieved through the integration of attributes that adapt to their environments and activities [6]. This design philosophy considers the distinct needs of children, who are in a constant state of growth and development and are naturally active and more vulnerable.

Creativity and technique are intrinsic to the children’s fashion design process, but a lack of understanding can impede the advancement of the design discipline [13]. Design elements and principles, such as space, line, shape, form, colour, texture and pattern, serve as dynamic tools shaping the aesthetic and functional aspects of a garment. The Design Council developed a Double Diamond design methodology to clarify the complexities involved in the design process [14]. According to their perspective, design is a dynamic and non-linear process, constantly influenced by various factors and ongoing feedback that can improve and polish the initial stages. This process is organised into two diamonds of divergent and convergent thinking each, comprising four essential phases: Discover, Define, Develop, and Deliver (Figure 1).

The initial phase has extreme significance, requiring a clear understanding of the problem at hand. Engaging in discussions and spending time with the consumer and user is crucial for gaining insight into their clothing usage, requirements, strengths and aspirations for the product. Cunha and Broega [10] underscore the significance of understanding user interaction and connection within the functional fashion design process. This idea is supported by Bezerra et al. [15], who emphasise the importance of understanding the user’s body, especially when it corresponds to children. This phase significantly influences the ‘Define’ phase, as it is crucial to establish goals, objectives, and restrictions based on user requirements. This phase will help define the problem, its challenges and opportunities.

According to the Design Council [14], in the second diamond, the ‘Develop’ stage encourages new responses to the problem already defined through the search for inspiration and collaborative work. In the context of fashion design, this involves exploring materials and comfort specifications. It is important to take inspiration from diverse sources, analyse fashion trends, and evaluate existing products in the market.

According to Shaharuddin and Jalil [5], children’s clothing design centres around ensuring comfort, convenience and safety. Comfort, a paramount consideration in the world of clothing, is intricately linked to consumer needs and decisions taken during design processes, namely, materials selection and fit [10]. These factors influence not only the consumer’s overall wellbeing but also their performance and efficiency [16]. The incorporation of these additional characteristics reinforces the overall wearing experience and improves the effectiveness and utility of the apparel, leading to superior outcomes and experiences [4]. According to Cunha and Broega [10], it is crucial to comprehensively address comfort, encompassing its psychological and aesthetic dimensions, as well as sensorial, thermo-physiological, and ergonomic aspects.

Specifically in children’s clothing, there is a notable preference for natural fibres, with cotton being the foremost choice. Its inherent characteristics, such as sensorial and thermal comfort, make it exceptionally suitable for children’s delicate skin. Moreover, it aids in preventing the exacerbation of certain dermatological pathologies [2]. While cotton offers softness and breathability, the dynamic nature of children’s activities demands additional functionalities in their clothing. Functional textiles are significantly important in addressing these diverse requirements.

Integrating functional properties into children’s clothing can improve the overall performance and durability and is decisive in safeguarding their wellbeing and supporting ongoing growth. Due to their constant development, children are uniquely vulnerable to environmental contaminants. Their organs are more delicate and susceptible, resulting in a distinctive metabolic response to chemicals compared to adults [17]. Consequently, any disruptions to their health during this critical developmental phase can potentially lead to irreversible damage in the future [18]. When designing for children, it is essential to contemplate how clothing may impact their development [7].

The last point of the process corresponds to ‘Deliver’, which involves testing different solutions on a small scale, discarding what does not work and improving what might work. From a fashion design point of view, this phase can include the construction of ideas, prototyping plans and the creation of clothing, taking into consideration manufacturing processes and fitting considerations. As emphasised by Lee and Jirousek [13], when considering a specific demographic and body shape, a fashion designer must also consider the feasibility of production. This involves assessing the technical structure of the piece and its production costs while concurrently creating an aesthetically pleasing physical form.

In conclusion, the design process of children’s products is complex and demands a nuanced approach. Clothing must protect while allowing for a certain level of risk, recognising the importance of adopting resilience and learning through experiences. Moreover, clothing designed for children should not only meet their expectations but also actively promote exploration and curiosity. The challenge lies in creating products that, while adhering to safety standards, encourage children to interact with their environment. This ensures that the clothing supplies its intended functions while inspiring a sense of curiosity and discovery [7].

4. Functional Textiles

Clothing demonstrates inherent characteristics stemming from the design process, affording essential protection against external elements, akin to a second skin. However, the emergence of demanding environmental conditions has spurred the requirement for novel functional attributes that conventional textiles do not satisfy [19]. This has also accentuated the desire for consumption driven by the pursuit of distinction, technological advancements, and intelligence [20]. Researchers are consistently exploring possibilities to increase and expand the functionalities of fabrics [21].

The terminology related to functional textiles and smart textiles is a subject of debate in the literature. Ismar et al. [22] argue that a distinction exists between functional textiles and smart textiles. According to their perspective, functional textiles derive their functionality through the inclusion of specific materials or finishing processes. In contrast, smart textiles exhibit a reactive nature, answering to external conditions or stimuli. Supporting this viewpoint, Ghosh et al. [23] propose that functional textiles are classified as technical textiles, prioritising performance and functional characteristics over aesthetic considerations. In opposition, smart textiles can perceive and analyse signals, enabling them to adapt to changing conditions. However, the authors emphasise that while all smart textiles are inherently functional, not all functional textiles meet the criteria to be considered smart.

Based on the insights provided by the authors, an analysis was conducted of the main functionalities applied to textiles, along with the main materials and products used to achieve these functionalities. This information is presented in

Table 1. Comprehensive overview of features, products, and technologies of functional textiles.

Functionality	Description of Functionality	Materials and Products	Source
Abrasion Resistance	Provides resistance against wear and tear.	High-strength fibres, polyurethane (PU)	[23]
Antimicrobial	Inhibits the growth of bacteria, fungi and/or virus on the fabric: antibacterial, antifungal and antiviral, respectively.	Nanoparticles NPs (e.g., nano silver, nano zinc oxide, nano titanium dioxide), chitosan, essential oil, natural dyes, enzymes	[24,25,26]
Antistatic	Reduce or restrict the build-up of static charge.	Conductive polymers, hydrophobic and hydrophilic components, NPs	[23,25]
Camouflage	Adapts colour and pattern to blend with the environment.	Chromic pigments, indium tin oxide, crystal microcapsules, conductive polymers (e.g., polypyrrole)	[27,28]
Colour-changing	Changes colour in response to external stimuli (temperature, humidity, UV source, etc.).	Chromic pigments (thermo, hydro, photochromic, etc.), chromic compounds	[16,28]
Dirt-resistant	Removes or prevents the accumulation of dirt and stains.	NPs, photocatalytic materials, polymers, enzymes	[23,25]
Electro conductivity	Exhibits electrical conductivity for various purposes.	Conductive materials (carbon, copper, aluminium, titanium), conductive polymers, sensors, NPs	[16,25]
Electroluminescence	Emits light in response to an electric current.	Electroluminescent materials, conductive layers, LED integration, polymer optical fibres	[23,29,30]
Electromagnetic Shielding	Protects against electromagnetic interference.	Shielding materials, conductive polymers, metals, metal oxides	[16,23]
Ergonomics	Specifically designed to improve wellbeing, comfort and interactivity.	Adjustable or removable details, different patternmaking, anthropometric measurements, elastic fabrics, interactive applications	[15,31]
Flame Retardance	Resists ignition and combustion.	Flame-resistant fibres, flame-retardant finishes, NPs	[23,25]
Fluorescent and Phosphorescent	Absorb UV light and re-emit it as visible light.	Fluorescent and phosphorescent pigments	[28,32]
Health Monitoring	Monitor or collect data related to the wearer’s health.	Sensors, conductive threads, data science tools, conductive polymers	[22,29]
Insect-repellent	Repels insects to protect against bites and potential vector-borne diseases.	Insect-repelling chemicals, natural dyes, synthetic insecticides, essential oils	[23]
Odour-resistant	Inhibits the growth of odour-causing bacteria and fungi.	NPs, antimicrobial components, chitosan, essential oils, natural dyes	[16,23]
Photovoltaic	Converts sunlight into electricity for powering devices.	Photovoltaic cells, solar textiles	[23]
Pressure Sensing	Detects and measures pressure or vibration applied to the fabric.	Piezoresistive materials, pressure sensors	[16]
Reflective	Reflect light back to its source, making it highly visible in low-light or dark conditions.	Reflective colourants, retroreflective materials	[30]
Shape-changing	Changes shape in response to external stimuli.	Shape memory polymers, actuators, chemically cross-linked polyethylene/polypropylene blends	[16,23]
Stretch or Elasticity	Stretch and recover the fabric, providing comfort and flexibility in movement.	Elastane, elastomeric fibres, elastic threads, knitted fabrics	[23]
Thermal conductivity	Improve heat conduction properties in textiles.	Graphene-coated, conductive materials	[22,23]
Thermal Insulation	Reduces the transfer of heat through the fabric.	Insulating fibres, aerogels, thermal barriers	[23]
Thermoregulation	Regulates body temperature.	Phase-change materials (PCM), NPs	[33,34]
UV Protection	Protects against harmful ultraviolet (UV) radiation.	UV-absorbing components, UV-reactive dyes, chitosan, natural dyes, NPs, inorganic compounds	[35,36]
Waterproof	Impervious to fluids, preventing penetration in the fabric.	NPs, polymers, PU, metals, metal oxides	[16,23]
Water repellent	Repels fluids, but over time and with pressure, fluids can be absorbed by textiles.	Chemical compounds such as carbon-fluorine bonds, hydrophobic fibres, NPs, polymers	[37,38]
Wrinkle-Resistant	Resists the formation of wrinkles and creases in the fabric.	NPs, resins, chitosan	[23,25]

.

A diverse range of functional materials, including organic or inorganic agents, polymers, nanomaterials and electronic materials have been developed to achieve functional textiles through functionalised technologies [19,39]. In addition to health and protection, research also explores design aspects like versatile usability, responsive elements (such as colour-changing and glow-in-the-dark), and interactive applications. As functional textiles evolve, ensuring their safety becomes crucial for widespread use [19].

Nanotechnology has contributed to the development of multiple functionalities in fabrics, such as antimicrobial and antistatic properties, wear resistance, ultraviolet (UV) protection, and flame retardancy [39]. Nanomaterials, whether engineered or natural, are defined as materials possessing structures or attributes that manifest on the nanoscale. At this level, materials frequently demonstrate distinctive and improved characteristics in contrast to their larger-scale equivalents. However, it is important to acknowledge the potential risks to the ecosystem and human cells [40,41] due to the lack of safety regulations regarding toxicological information, which may particularly affect the wellbeing of babies and children [39].

In addition to the materials and products listed in Table 1, various technologies are discussed in the literature as effective methods to achieve specific functionalities in fabrics. These include specific coatings that can be utilised to achieve abrasion resistance, thermoregulation, UV protection, or waterproofing; spinning methods aimed at imparting shape-memory or elasticity characteristics; and the encapsulation of fibres with substances such as essential oils to confer antimicrobial or insect-repellent properties.

According to Shaharuddin and Jalil [5], children’s clothing should provide wellbeing, comfort, safety, durability, and ease of care, all while maintaining a sense of style and playful interest. From the set of features presented previously, six specific functionalities in textiles were selected that could be applied to children’s clothing: antimicrobial, ultraviolet, thermoregulation, waterproof, ergonomics, and colour-change. The subsequent sections provide an overview of the studies conducted on these explorations, encompassing a generic perspective, with a particular emphasis on the medical, comfort and playful aspects of the functionalities.

4.1. Functional Textiles for Improved Protection and Wellbeing

A significant portion of research in functional textiles is dedicated to improving protection, health and overall wellbeing. Due to the heightened sensitivity and vulnerability of children during their development, the integration of such textiles into children’s clothing holds paramount importance.

4.1.1. Antimicrobial Textiles

Among the most sought-after and extensively investigated attributes in functional textiles are antimicrobial properties. According to Gulati et al. [40], antimicrobial textiles can either eradicate microorganisms (biocide) or inhibit or reduce their growth (biostatic). The authors suggest that, for clothing application, biostatic fabrics are preferable, preserving skin flora without adverse effects. On the other hand, biocidal fabrics, causing direct microorganism mortality, find greater recommendations for medical or environmental applications.

Perspiration is a natural and anticipated occurrence during daily clothing use. To protect fabrics or garments from the generation and persistence of odours, including those caused by fungi, bacteria, and other microorganisms, the integration of antimicrobial textiles is essential [35].

The antimicrobial property has been a growing research topic in the textile field, with a broad spectrum of studies investigating the achievement of this property in fabrics. Various approaches have been investigated by researchers to develop and enhance antimicrobial textiles, including the incorporation of metal nanoparticles (MNPs), particularly silver nanoparticles (AgNPs) [25,39], dyeing with plant-derived dyes [26,42], the incorporation of essential oils into fibres [24], and the utilisation of materials such as cyclodextrins and their derivatives, lignin, and chitosan [40].

Blending antimicrobial textiles with design elements like colours and prints has the potential to contribute to innovation and competitiveness within the children’s segment of the textile industry. However, there might be limitations in terms of awareness and utilisation of such products [40].

4.1.2. Ultraviolet Protective Textiles

In addition to the antimicrobial properties, the study of UV radiation protection is also an important theme explored in the textile area. UV protective textiles are designed to improve protection against the harmful effects of UV radiation, addressing risks to both textile and human health, especially the skin [35]. Engineered to block or absorb UV rays, these textiles become crucial in mitigating the potential risks of prolonged or excessive sun exposure. Unchecked UV radiation can lead to various skin issues, including pigmentation, sunburn effects, premature ageing, skin cancer, and DNA damage [35,36]. The efficacy of UV protection in textiles is influenced by several factors, such as the choice of fibre (some fibres, like polyester and nylon, offer inherently better shielding against UV radiation), the material’s structure (greater weave/knit tightness or thicker fabrics), the colour of the textile (darker colours tend to absorb more UV radiation than lighter colours), applied treatments, the types of textile dyes used and conditions of dyeing processes [36,43].

Despite the effectiveness of numerous synthetic finishing agents in creating UV-protected textiles, their environmental impact raises concerns when released as effluents, posing risks to the ecosystem [42]. Therefore, there is a growing exploration of environmentally friendly materials [35]. Natural dyes, in addition to antimicrobial properties, can also exhibit commendable protection against UV radiation [44].

Clothing with proven UV protection, beyond what conventional textiles offer, has compelling evidence in safeguarding children’s skin. A study by Harrison et al. [45] found that consistent use of ultraviolet protection factor (UPF) 30–50+ clothing, covering at least half of children’s bodies, significantly reduces pigmented mole development. Wearing this clothing for 3.5 years prevents almost one-quarter of moles compared to children without such protection, implying a reduced risk of future melanoma in these children.

4.1.3. Thermoregulating Textiles

Comfort is a fundamental aspect for human wellbeing [46]. Providing an optimal and comfortable thermal environment is essential for ensuring the health and development of children. Thermo-regulating textiles, engineered materials designed to adjust to environmental conditions, contribute to overall wellbeing by providing thermal comfort and reducing energy consumption. Thermal comfort refers to the psychological state of contentment with the ambient temperature, avoiding extremes of cold or heat [34].

During normal wear, the body’s insensible perspiration generates a continuous heat and moisture vapour flux, crucial for thermoregulation and thermal comfort [46]. Recognising and addressing thermal comfort contributes to children’s physical wellbeing and their focus and engagement in various activities. This is because ensuring an ideal thermal environment influences emotions, productivity, and overall comfort, creating a more favourable atmosphere for learning and play.

Individual comfort levels with similar thermal sensations vary due to factors such as physical activity, metabolic level, and temperature susceptibility [34]. The authors note that fabrics excel in either breathability or moisture absorption, rarely balancing both. However, a study conducted by Jamshaid et al. [46] developed interlock fabrics featuring with a TransDry (TransDry is a patented technology that combines the comfort of cotton with high-performance moisture-wicking capabilities), incorporating hydrophilic and hydrophobic yarns alternately. This strategic design optimises the comfort properties of knitted fabric by overcoming the usual trade-off between breathability and moisture absorption.

Various types of textiles have been studied for their potential in thermoregulatory clothing, including radiation-controlled, conduction-controlled, dual-mode, and responsive textiles [27,33]. Overall, thermo-regulating textiles are crucial in enhancing comfort, performance, and wellbeing in various aspects of daily life. Their ability to adapt to changing conditions makes them an asset in achieving optimal comfort and functionality.

4.1.4. Waterproofing Textiles

Waterproof textiles are specially engineered fabrics treated or designed to repel liquids, preventing penetration into the material. Waterproofness represents an extreme level of water resistance [38]. Waterproof clothing for children goes beyond mere protection from the water; it contributes to their health, safety, and enjoyment, fostering a positive and active lifestyle. Investing in quality waterproof clothing ensures that children can explore and play freely, regardless of the weather.

Waterproof fabrics, besides blocking external water, must also provide breathability for effective water vapour diffusion. These dual characteristics are crucial for regulating body temperature, managing heat efficiently, and protecting against external elements [16]. According to Loghin et al. [47], testing methods, including hydrostatic pressure and simulated rainfall are used to determine fabric waterproofness. The common hydrostatic pressure test requires a minimum of 5000 millimetres (mm) of water column (water column represents the height of a column of water that the fabric can support before water begins to penetrate) to be considered waterproof, with high-quality materials achieving values up to 30,000 mm.

Some studies have been carried out to improve the waterproof properties of fabrics. Joshi et al. [37] enhanced fabric waterproofness by coating woven polyester structures with solvent-based polyurethane (PU). This study also incorporated natural elements, adding anti-UV and antibacterial properties. In addition to improving water resistance, PU can be used to absorb UV radiation. It can also create a reflective barrier that reduces the amount of UV light absorbed by the fabric or increase the durability of UV protection. Another research on outdoor clothing fabrics found that applying a hydrophilic treatment to laminated nylon woven fabrics improved their waterproof-breathable properties [38].

4.2. Functional Textiles and Clothing for Children’s Development and Interaction

The incorporation of functional textiles in children’s fashion design process not only prioritises the thermal comfort, safety, and wellbeing of young users but also addresses the dynamic and active nature of children’s lifestyles, providing practical solutions to meet their unique needs and development phase.

4.2.1. Ergonomic Functionalities

Ergonomics, prioritising physical comfort and wellbeing, is crucial in children’s clothing design, accommodating their dynamic activities like running, jumping, dancing, and playing [15,48]. The dimensions of the human body, known as anthropometry and the study of body movements, referred to as biomechanics, are crucial factors often forgotten in this regard [48]. Given the ongoing development of children’s bodies and minds, their physical and mental activities significantly influence their overall growth [7]. Inconsistent sizing in children’s garments can lead to fit problems and discomfort, hindering natural movements and potentially causing health problems [15].

Designers and consumers increasingly prioritise the functionality and style of fabric materials in children’s clothing, with a focus on stretchable fabrics and loose-fitting clothes to accommodate rapid body growth [31,49]. The use of elastic fabric materials is common and suitable for a wide range of children’s clothing [49]. Precise anthropometric measurements are also essential in the design process. They allow for the customisation of clothing to meet the unique requirements of the wearer, considering factors such as body structure, mobility, proper respiration, and blood circulation [15,49].

Mukhopadhyay [48] emphasises the importance of integrating ergonomics into the apparel design process, starting from the initial stages and extending throughout the fashion industry, specifically addressing the challenges associated with the rapid growth of children. Regrettably, current children’s clothing often lacks anthropometric evaluations, resulting in poor fit and diminished comfort [15].

Given the swift growth of children, a dynamic clothing design approach is essential, incorporating principles of ergonomics and functionality [31]. Clothing should not only prioritise comfort but also encourage exploration, promoting child development through interactive and explorative elements [7].

4.2.2. Colour-Changing Textiles

Colour-changing materials experience modifications in electron density or molecular arrangement induced by external stimuli, resulting in a shift in colour, with the material returning to its initial state when the stimulus reduces or disappears [16,28]. These materials can be categorised as photochromic, thermochromic, electrochromic, solvatochromic, halochromic, tribochromic, and piezochromic. Each category responds to specific stimuli, namely, UV light, temperature, applied fields or currents, among others [16,23], and offers potential applications in monitoring, safety, and comfort [28].

In a study conducted by Garcia-Souto and Dabnichki [50], thermochromic pigment applied to fabric demonstrated potential as a non-intrusive wearable system for early fever detection in young children, monitoring diverse skin temperatures. In addition to the monitoring function, chromic textiles prove to be interesting tools for learning and stimulation, especially for children, transforming how they interact with clothing [28,51]. However, some chromic products may lack colour fastness, leading to a gradual loss of functionality over time. A study conducted by Cabral et al. [51] addresses this concern and highlights the potential of exploring colour interactivity by creating changeable colour palettes and patterns, incorporating pigments with variable levels of reversibility and permanence. This insight underscores creativity in the design process and contributes to the increase of chromic products life cycle. Beyond technical aspects, the use of colour-changing materials in children’s clothing can introduce interactive and educational functionalities, fostering curiosity and contributing to cognitive development.

In addition to the functionalities previously described, numerous other properties are being explored, such as flame retardancy, anti-odour capabilities, insect-repellence, reflective properties, and more. Fabrics with these properties aim to provide improved functionalities by adapting to diverse environmental conditions and consumer activities [23].

5. Analysis of Functional Children’s Clothing Brands

Despite extensive research in the field of functional textiles and efforts to mitigate the environmental footprint of this industry, the practical application of these findings in the realm of children’s clothing appears to be at an early stage. In this regard, qualitative research was conducted on children’s clothing brands that emphasise the functionality of their products (

Table 2. Analysis of products, functionalities, textile materials and technologies across functional children’s clothing brands.

Brands	Target	Functionalities	Textile Materials	Technologies
SilverGuard https://www.silver-guard.co.uk/	Underwear	Antimicrobial; anti-odour	Cotton, silver threads	Self-sanitising IONIC+ (X-STATIC®)
Fiffy https://www.fiffybaby.com/	Underwear	Antimicrobial; anti-odour	Cotton	“Natural Technologies”
Le Petit Chiffon https://www.lepetitchiffon.pt/	Underwear	Adjustable clothes	Organic cotton	Patternmaking
Frugi https://www.welovefrugi.com/	Underwear Outerwear Swimwear	Adjustable details; Interactive appliques; Reversible pieces; Waterproof; Reflective details; (harmful chemicals free)	Organic cotton, recycled polyester	Water-repellent and Fluorocarbon free finish/Patternmaking
Sustain by kat https://www.sustainbykat.com/	Outerwear	“Good for skin”/promote wellbeing; (harmful chemicals free)	Organic fibres	Plant dyes with ayurvedic processes
Bonsie https://www.bonsie.com/	Underwear Wear to surgeries and treatments	“Promote easy skin-to-skin contact”; hook & loop closure; (harmful chemicals free)	Diverse materials	Patternmaking
Eczema Clothing https://www.eczemaclothing.com/	Underwear Outerwear	Flat seams; latex free; no internal label; (harmful chemicals free)	Organic cotton, Tencel	Patternmaking
Happy Skin https://www.happy-skin.com/	Underwear	Thermoregulating; Lightweight; Hypoallergenic	Tencel, cotton, elastane	DreamSkin®
DreamSkin Health https://www.dreamskinhealth.co.uk/	Underwear	Thermoregulating; Ultra-lightweight; hypoallergenic	Medical grade silk	DreamSkin®
Nununu https://www.nununu.com/	Outerwear	Reversible pieces; Gender neutral	Cotton	Patternmaking
Smartwool https://www.smartwool.co.uk/	Underwear Outerwear	Resistance; Thermoregulating; Breathable; Odor-resistant; UV protection; Fire-resistant	Merino wool, polyester, nylon	Indestructawool™; Inside-Out Design with merino wool
Petit Pli https://www.shop.petitpli.com/	Outerwear	Clothes with origami structure that “grows with the child”; Rainproof; Resistance; Reflective details; (harmful chemicals free)	Recycled polyester	Patternmaking; Ripstop fabrics
Ker Sun (multi-brand) https://www.ker-sun.com/	Outerwear Swimwear	UV protection	Diverse materials	Zinc oxide protection
Waterproof World (multi-brand) https://www.waterproofworld.co.uk/	Outerwear	Waterproof; Adjustable details; Reflective details; Breathable	Diverse materials	Polyurethane (PU) coating
Muddy Puddles https://www.muddypuddles.com/	Outwear Swimwear	Waterproof; Breathable; Durable; Reflective details; UV protection	Recycled polyester	PU coating; BIONIC FINISH®ECO
Kidunk https://www.kidunk.com/	Outerwear	Waterproof; Breathable; Durable, Reflective details; Removal details	Recycled plastics	Teflon EcoElite™
Éclipse https://www.eclipseglove.com/	Outerwear	UV protection; Thermoregulating; (harmful chemicals free)	Recycled polyester, elastane	No information
The good day lab https://www.thegooddaylab.com/	Outerwear	Stain and liquid-repel; Anti-shrink; Breathable	Cotton, elastane	Clean Shield Technology
Spellbound https://www.spellbound.ee/	Outerwear	Prints with colour change materials (glow-in-the-dark)	Left-over natural materials	No information
Illuminated Apparel https://www.illuminatedapparel.com/	T-shirts	Interactive UV glow torch pen to draw onto the glow canvas panel on the t-shirt	Cotton	No information
Babyglow 1	Bodysuit	Changes colour when baby’s temperature is too high	Cotton	No information

¹ Isolated product.

).

To understand the functionalities inherent in children’s clothing products and the main technologies used in the market, four research indicators were developed for analysis on the brands’ websites. All information about the brands was extracted from their online platforms. The four selected indicators are as follows:

• Target: examined through product indications to determine the principal use of clothing. This assessment aims to determine whether the clothing is intended for internal or external use. This indicator is crucial for understanding whether the functionality is geared towards direct contact with the skin, protection against external elements or other specific uses.
• Functionalities: observed by assessing the principal features emphasised by the brands. This assessment aims to determine whether to provide comfort and wellbeing or to promote interaction and cognitive development.
• Textile materials: analysed by the type of material used for functional clothing.
• Technologies: observed through the main technologies used or applied to the materials to achieve the functionalities presented.

After interpreting the results, this information was cross-referenced with the previous research about children’s fashion design process and functional textiles, discussing the role of the designer in creating functional children’s clothing.

After conducting a thorough market analysis of children’s functional clothing, 21 brands/products were identified that meet these criteria. This analysis indicates a principal focus among children’s clothing brands on functionality through the patternmaking of clothing items.

• Patternmaking

Key aspects highlighted include the incorporation of adjustable or removable details in clothing to accommodate the child’s rapid physical growth, the utilisation of interactive applications to promote cognitive development, strategic placement of labels to improve physical comfort and the careful crafting of garments to ensure a comfortable fit. In the case of the Bonsie brand, the patternmaking design is crafted to facilitate skin-to-skin contact between the baby and mother in a convenient and accessible manner at any time and place. This is possible due to the simple design of the piece, which has a Velcro opening on the chest. The brand underscores the significance of this patternmaking feature, especially for babies with medical complications and disabilities in a hospital situation. This patternmaking allows professionals to easily place sensitive medical equipment on the baby without the need to remove all clothing.

In contrast, the Petit Pli brand uses a space-inspired design with mixed fibres, compact seams, and high-resistance materials to imbue the clothing with the functionality to adapt to the child’s growth. With an origami structure that offers freedom of movement and resistant material, this design allows the same piece to accommodate various sizes.

Furthermore, a consistent theme within the identified brands is the commitment to avoiding the use of toxic chemicals, exemplified by brands such as Frugi, Sustain by kat, Eczema Clothing, Happy Skin, Petit Pli and Éclipse. Although not classified as a functionality, this commitment holds significant importance for wellbeing and reflects a sustainable brand position [52]. The avoidance of toxic substances aligns with health-conscious practices and has the potential to prevent or alleviate symptoms of certain pathologies, particularly those related to dermatological concerns.

• Waterproof

The primary functionality highlighted includes waterproof protection, followed by UV protection, thermoregulation capacity, reflective or colour-change materials and antimicrobial/anti-odour properties.

Frugi, Petit Pli, Waterproof World, Muddy Puddles and Kidunk showcase waterproof properties in their clothes. All these brands specify a hydrostatic pressure value of 10,000 mm water column on their websites, except Petit Pli, where this information was not found, and Kidunk, which indicates a value of 3000 mm water column. According to Lighin et al. [47], the value presented by the Kidunk brand does not meet the minimum requirement for a fabric to be considered waterproof, which is 5000 mm of water column. On the other hand, The good day lab brand offers clothes with liquid-repellent properties, although they are not waterproof.

There is a distinction between waterproof textiles and water-repellent textiles. The lack of clear information regarding this difference can be confusing for consumers. Waterproof materials are impervious to fluids, preventing penetration. On the other hand, water-repellent materials, when exposed to water, form droplets that can be effortlessly removed from the fabric’s surface. However, with prolonged contact or a significant pressure difference, water-repellent materials may absorb water [47].

• UV protection

Regarding the UV protection property, all brands that present it report UPF 50+ protection, except for Smartwool, which only states that merino wool, a fibre used in greater quantity in its products, helps protect against UV radiation.

While brands may mention specific functionalities, the way these functionalities are integrated or applied to clothing is often poorly explained by most brands. The absence of clear information about the durability of the functionality over time, the methods used for testing and validating the functionalities, and the specific technologies, materials, and products used to achieve functionalities presents a challenge for consumers who are looking for details about the functional attributes of children’s clothing and their potential effects on children’s wellbeing.

• Thermoregulation

As an example, the brand Sustain by kat claims that the selection of plant-dyed clothing was “made with certified organic materials and ayurvedic processes (that) promote wellbeing”. According to Roopashree et al. [53], ayurverda corresponds to a therapeutic process in which the treatments prescribed are resources from various natural sources. In this case, the brand refers to the use of plant dyes that have medicinal properties. However, the specific details about properties and how these ayurvedic processes are incorporated into the clothing remain unclear on the brand’s website.

Another example of lack of information corresponds to two of the brands that present thermoregulation properties, but they do not specify their technologies. Smartwool attributes this property, along with breathability, odour resistance, UV protection and fire resistance, to the qualities of merino wool fibre. On the other hand, Éclipse does not provide any explanation. In contrast, DreamSkin Health is a brand that presents the functionality and technology used to obtain it, as well as scientific studies that prove it. This brand uses a technology called DreamSkin, characterised by a coating capable of managing moisture from damaged skin. It releases moisture when conditions are hot and retains it when temperatures drop. The brand underscores on its website that it conducted a study involving standardised tests on artificial skin with eczema to validate the effectiveness of this technology [54,55]. According to the study, significant improvements were found in the treated skin area, with a significant increase in skin hydration observed after 14 days, peaking on the 7th day. Furthermore, the study demonstrated a 40% improvement in cell viability after 24 h compared to untreated textiles [55].

DreamSkin Health has introduced the Happy Skin brand as a more economical version, utilising the same technology with one key distinction. In DreamSkin Health, the technology is applied to medical-grade silk fabrics, whereas in Happy Skin, it is applied to a blend of Tencel and cotton. This strategic adaptation allows Happy Skin to maintain the benefits of innovative technology while offering a more budget-friendly option.

• Colour-changing

Another prevalent functionality in children’s clothing brands is the incorporation of reflective materials. According to Cui et al. [49], the use of brightly coloured fabric materials in children’s clothes aims to attract attention and increase the visibility of children, promoting increased awareness and protection for them. Reflective details strategically incorporated into the brands’ clothing increase this protection, improving the visibility of the user in situations where the risk of being unseen is high. Various technologies can be effective for this purpose, not limited to reflective materials. A study conducted by Studzińska et al. [30] suggests the use of polymer optical fibre as an efficient active light source. The authors concluded that this technology offers children significantly enhanced safety in a traffic environment compared to reflective elements, due to its broader visibility range.

Additionally, colour-changing materials serve these protective functions, contributing not only to the promotion of safety but also promoting creativity and cognitive development. For example, the Illuminated Apparel brand includes a UV light pen in their products to encourage interactivity. The Spellbound brand explores materials that glow in the dark to create new prints on clothing, supporting children’s exploration. In contrast, the Babyglow product changes colour when the user has a temperature considered above normal, alerting caregivers to potential health problems. However, there is limited information available about this product.

• Antimicrobial

The antimicrobial activity for integration or application in functional textiles is a growing research topic; however, this property is not readily found in brands that specialise in children’s clothing. Only two brands were identified that incorporate this functionality in their children’s products, namely, SilverGuard and Fiffy. Only the first brand provides specific information about the technology it uses to achieve the antimicrobial property, referred to as IONIC+ Silver (formerly known as X-STATIC^®). Textile materials incorporating this technology are developed using silver fibres, which possess antimicrobial properties, creating a shield that inhibits the growth of bacteria and fungi [29,56]. The antibacterial efficacy of these fibres can achieve a 99% reduction within 12 h [56]. According to Anis et al. [29], this technology was initially designed for soft surface textiles in hospital environments.

As anticipated, cotton stands out as the predominant fibre in children’s brands, particularly in underwear. Each brand showcased demonstrates a dedication to children’s comfort, with the majority also exhibiting environmental consciousness. This aligns with the findings of Jalil and Shaari [6], who assert that functional clothing performs as a practical and sustainable solution.

Despite the extensive body of research in the field of functional textiles, there is a noticeable lack of integration or application of these functionalities in the children’s clothing market for daily use. However, some brands are already investing in functional textiles, albeit without a broad reach or a wide diversity of products. One reason for this limited adoption may be the designers’ lack of knowledge regarding the availability of existing technologies and materials with added functionality. According to Cunha and Broega [10], a solid understanding of the user, materials, the product itself and its construction makes the development of functional products more viable. This assertion can be corroborated by Rice [7], which emphasises that designers should consider all aspects of child development, with a particular focus on safety and warnings.

6. The Role of Designers in Functional Children’s Fashion

In today’s fashion landscape, designers have a significant impact in shaping not only the aesthetics but also the functionality and sustainability of children’s clothing. According to Jalil and Shaari [6], designers believe that functional children’s clothing can be designed with fashionable aesthetics to serve their intended purpose. However, they also acknowledge that factors such as higher pricing, limited options in terms of choice and colour combinations, as well as restricted access to sustainable clothing, are critical considerations for consumers.

The developing functional children’s clothing needs careful consideration of multiple factors. Figure 2 highlights a set of key points along five topics: children’s needs, functionality, environment, clothing and user experience.

Designers must have a deep understanding of the target audience and their preferences. When discussing baby or children’s clothing, it is crucial to consider both the user and the consumer, as young children cannot purchase their clothes. According to Shaharuddin and Jalil [57], the consumption of children’s clothing is on the rise. It is estimated that most parents buy clothes for their children at least once every 4 to 5 months. One of the primary drivers for the increased consumption of children’s clothing is the rapid growth experienced by children [15]. This rapid physical evolution necessitates a constant adaptation of clothing to accommodate the different stages of their development [58].

In addition to the practical considerations of growth, purchasing children’s clothing also carries significant emotional value and concern. Berry et al. [59] highlight that the consumption behaviour of children’s products reflects the societal values placed by parents. This motivates parents to pay meticulous attention to their children’s needs and be discerning in selecting clothes that suit them.

Additionally, research on materials and technologies is a critical aspect of the design process, focusing on understanding the unique attributes of textile materials applicable to the design process. Continuous exploration and updates on emerging textile materials are particularly crucial, as these innovations often serve as decisive elements in product differentiation. A strong understanding of textile materials is essential for the design team to craft solutions that align with the specifications across functional, formative, and aesthetic dimensions [10]. This depth of knowledge ensures that the final design meets and exceeds the required standards at various levels, contributing to the overall success and innovation of the design.

Several studies emphasise the crucial role of designers in adopting sustainable design principles throughout all stages of the creative process [5,60,61]. This paradigm shift is vital for advancing the way resources are developed, produced, applied, used and managed at the end of their life cycle [60,61]. However, expertise in materials and technologies is not only significant for sustainability but also for functionality. Ismar et al. [22] propose that promoting innovation in the creation of wearable electronic textiles requires an interdisciplinary research approach, involving collaboration among experts from diverse fields related to this product. Júnior et al. [16], support this notion by asserting that the development of advanced materials needs an approach from multiple disciplines.

The interdisciplinary methodology is applicable to the advancement of functional clothing for children. The Petit Pli brand is a notable example, as the brand asserts that its team comprise aeronautical engineers, neuroscientists, and designers, dedicated to the development of patented innovations.

Creative thinking is an integral facet of the functional apparel design process, transcending the confines of conventional approaches to promote innovative solutions. Nevertheless, in the face of the increasingly intricate challenges confronting global industry and society, relying solely on designers’ skills is insufficient [62]. The complexity of contemporary issues, involving environmental sustainability, technological advances and social changes, requires a broader, interdisciplinary approach, especially when designing clothing for children. Collaborative efforts that extend beyond traditional design boundaries become essential. Fashion designers must actively participate in interdisciplinary partnerships, drawing on the experience of professionals in different areas, and covering a spectrum of knowledge and skills [63].

However, interdisciplinary work can often present challenges and conflicts among stakeholders [62]. According to Coulter [64], cases of successful collaborations between fashion design-based disciplines and more scientific disciplines such as engineering are limited. The author attributes this to variation in how results are measured and reported in each discipline. While the creation of research groups across different disciplines does not guarantee automatic innovation, lacking this multidisciplinary knowledge limits a project’s chances of success, highlighting the importance of creating an environment conducive to interdisciplinarity [62].

Although teamwork is crucial, designers are responsible for guaranteeing the continuous incorporation of functionality from the early stages of the design phase. This requires designers to possess a comprehensive and up-to-date understanding of the technical elements relevant to their projects, coupled with a clear and consistent vision. Designers must articulate the essential knowledge and intention behind their design decisions, providing a solid foundation for the collaborative process.

The result of this study is a framework that provides a clear and visual representation of the design process for functional children’s fashion (Figure 3). This design process is emphasised by the divergent and convergent thinking represented in the Framework for Innovation illustrated in Figure 1 [14]. In the context of functional children’s fashion design, the initial phase is centred on comprehending and exploring the needs of children and their surrounding environment. This facilitates the formulation of the challenge in diverse ways, involving both functional and aesthetic knowledge. Subsequently, prototyping arises from the various responses to the challenge, which are then subject to evaluation, requiring the rejection of ineffective solutions and the refinement of promising ones. This process is non-linear, and it is expected that underlying problems may necessitate revisiting previous phases, benefiting from collaborative efforts and interdisciplinary approaches throughout all stages.

Furthermore, to stay at the forefront of innovation, designers must maintain awareness of new technologies and advancements in the industry. This commitment not only allows for the continuous improvement and enhancement of design functionality but also positions designers to be ahead of industry trends, fostering the creation of innovative and unique solutions for children’s clothing.

By taking a proactive viewpoint in articulating their design rationale and expectations, designers can facilitate greater comprehension within the team and avoid any confusion or ambiguity. They have also the role of using active listening and empathy skills to understand and appreciate the views and feelings of others. This approach allows designers to guide and oversee the realisation of their envisioned clothing and ensure that the functionality is aligned with the design goals and objectives. Functionality ceases to be an afterthought and instead becomes an intrinsic component of the forthcoming piece.

By prioritising functionality from the beginning of the design process, designers can save time and resources in the long run and ensure proper implementation and evaluation. This approach aligns functionality with design standards and expectations, preventing the need for major revisions or adjustments later.

Designers guarantee that children’s clothing meets the specific needs and desires of the end-users and consumers by incorporating knowledge about functionality into the design process. Consequently, functionality allied to user adds value and impact to the brand and product, contributing to increased reputation and recognition in the market and solidifying the brand’s position as a provider of functional and purposeful children’s clothing.

7. Conclusions and Perspectives

The design process of functional children’s clothing is complex. It relies on a deep understanding of the user, as well as comprehensive knowledge of textile materials and technologies and interdisciplinary collaboration, though it can be challenging. Creative thinking remains pivotal, yet designers must acknowledge the complexity of global issues and adopt a broader, interdisciplinary perspective. While teamwork is crucial, designers have the responsibility of ensuring functionality from the early design stages. This proactive approach saves time and resources and aligns functionality with design standards, consumer preferences and user needs.

There is an extraordinary adaptability of diverse materials and technologies in serving a common functionality. This could expand the creative canvas for designers and underscores the paramount importance of adaptability and innovation in shaping functional garments tailored to the differentiated needs of children. However, despite growing research on functional materials and technologies applied to textiles, their application in children’s clothing design remains challenging. Research findings underscore a notable trend in children’s functional apparel brands, emphasising patternmaking features for everyday use. This addresses concerns about the rapid physical growth of children but reveals a potential oversight in addressing other specific needs, particularly concerning children’s skin health. Children have more vulnerable skin than adults, making them more susceptible to bacteria and fungi due to its fragility and incomplete development. Consequently, the example of antimicrobial clothing aligned with sustainability goals and prioritising non-toxic materials could contribute to the mitigation of symptoms related to dermatological pathologies, their treatment or prevention. By expanding the scope of consideration beyond patternmaking features, designers have the opportunity to significantly contribute to improving the overall wellbeing of children.

The study proposes a framework that delineates the procedural steps involved in creating functional children’s clothing. Designers are not only creators of aesthetic visions but also supervisors of sustainability, functionality, and innovation. It is emphasised that having prior familiarity with materials is an essential requirement for making informed decisions and effective advancement in this field. Designers must maintain awareness of new technologies and articulate the validation behind their design decisions. This facilitates collaboration and avoids ambiguity within the work team during the design process and improves communication with consumers, making it more transparent and accessible. As environmental consciousness grows and consumers become increasingly discerning in their choices, sustainable and multifunctional clothing options are prepared to become the new standard in children’s fashion. The gap between research advancements in functional textiles and their practical application underscores the urgent effort to connect them. Ensuring that improvements in functional textiles efficiently become part of the process of designing, producing and consuming children’s fashion can contribute to innovation and more thoughtful choices in the fashion industry.