*3.2. Robots Technology*

An under-studied field of research is the economics of technical change and technology management. A theory on the classification and evolution of technology considers the taxonomic characteristics of the interaction between technologies. The proposed classification makes an analogy with the evolution of parasites considering generalized Darwinism: parasitic technologies, commensal technologies, mutualistic technologies, and symbiotic technologies [24]. The classification of parasitic technologies is based on parasite–host relationships, and it has been shown that technologies with a high number of parasites have a high evolution. This theory provides a new perspective to explain and generalize the evolution of technology to sustain the competitive advantage of companies and nations [23].

The rapid development of service robots is mainly due to the fourth industrial revolution. In our current era, a person can obtain information and technology from the internet. However, due to the inherent speed of technological changes enjoyed by today's society, it is often overlooked and tends to be forgotten. All this technological research and development would change humankind and how it is and, according to Schwab [34], there are three main reasons why the ongoing fourth industrial revolution is changing our daily lives: The velocity in which current technology is evolving (exponential growth rather than linear growth), the breadth and depth the information has reached in today's society, and its impact on entire systems that are changing their paradigms from a micro to a macro level [7].

Before even starting to explain the new technologies that service robots are bringing and implementing, we need to go into depth into the levels that society will be affected, besides the tasks that will be executed by service robots. Taking up what was written by Wirtz et al. [7], alongside the micro-level, using service robots in different areas would bring advantages such as personalized service for each person/client, homogeneous quality service, accelerated learning, interconnection, to mention a few. Along the meso-level, service robots will become a solution to a market necessity, a commodity instead of a critical

source, and reduce payroll expenses. Along the macro-level, service robots will reduce the number of unattractive, time-consuming jobs that imply task repetition and the need to be present in one place due to the nature of the job (as a receptionist for the hotel), which would directly lead to a reduction in expenditures in general.

Across the literature reviewed in this paper, and taking into account the classification presented by Rubio et al. [35], we can resume the current uses, developments, and applications of service robots in the different operations areas as shown in Figure 5. This search used the ScienceDirect and Scopus databases during September 2021. It should be noted that the research carried out to establish a state of the art (SoA) for this work could be biased due to the large fields of application that service robots have. We include the leading research and developments that other researchers and peers have been undertaking; however, there may be more information about other applications not considered in this paper.

Delving into each area reviewed in the literature, the leading technologies applied to service robots can be identified. In the area of health, especially in the area of mental health, chatbots and virtual embodied artificial intelligence (AI)-supported psychotherapeutic devices are being tested to deal with anxiety and depression [36]. In addition to this, some of the disruptive technologies applied for the analysis of COVID-19 are the Internet of Medical Things (IoMT), data science and big data, blockchain, virtual reality (VR), telemedicine, 5G, AI, drones, and autonomous robots [37]. Nowadays, the creation of a mobile healthcare robot is possible thanks to AI, machine learning, facial recognition, and teleportation technologies [38]. There are arising openings for the operation of robotics to endorse ubiquitous healthcare that may reflect in cheapening medical expenses and adding the amenity of cases and people in general [39]. Alongside the education field, educational robots are implementing different learning models to enhance learning student performance. There is a wide variety of models such as adaptive learning, agent-based learning, and smart learning [40]. Other implementations are teleoperated, autonomous, and convertible robots to assist elementary school teachers during classes [41,42].

In the technology and kinetics area, unmanned aerial vehicles (UAV) require a ground control station (GCS), batteries, fuel cells, or hybrid power sources to work, as well as power management strategies for real-time monitoring of power consumption (rule-based and fuzzy logic strategies) [18]. Unmanned ground vehicles (UGV) require the development of robotic frameworks and platforms. Some of them are the Robot Operating System (ROS), Middleware for Robotic Application (MIRA), Yet Another Robot Platform (YARP), Lightweight Communications and Marshalling (LCM), Mission Oriented Operating Suite (MOOS), and Universal Robotic (Urbi), to mention a few [43]. Moreover, rescue robotics as autonomous robots should use field-deployable technologies and work in real-world environments [44]. Some service robots and robotic platforms tested in farms and factories use IoT, edge, and cloud computing through virtualization and AI technologies, pushing its commercial adoption [45,46].

There are also great opportunities and growth areas in the field of leisure and recreation, starting with the tourism sector; technologies such as information-centric networking, cloud computing, big data, blockchain, AI systems, and IoT are essential in the development of robotics in tourism [47]. Traditional hotels will have to transform into smart hotels and implement interconnectivity and interoperability to support business partners' applications, use big data to forecast revenues more precisely, and use instant translation devices to avoid miscommunication [48]. Not only will resorts' experiences change, but the shopping customer experience will change due to service robots. The implementation of neuroscience, business process automation, blockchain, digital twins, VR, AI, mobile robots, location-based wearables, and machine-to-machine interaction through IoT by organizations are going to provide immersive and personalized environments to consumers [49]. Moreover, the inception of humanoid service robots (HSRs) by companies will generate competitive advantages against their competitors and trigger compensatory consumer behavior [50]. However, the use of service robots is not only limited to experiences and

buildings; direct robot–human interaction will go further due to the use of wearable affective robots that will imitate cognitive competencies. Examples of these service robots are social robots that recognize emotions, affective robots, and intelligent brain wearables that recognize electroencephalography (EEG) data. They use natural language processing, pattern recognition, data mining, and other machine-learning techniques to achieve a human brain working mode simulation [51]. Lastly, service robots related to sexuality are no longer a fantasy due to the interest in human–robot interaction focused on sexual robots programmed with AI [52].

**Figure 5.** Uses and applications of service robots in different operation areas.

Thinking about smart urban environments, autonomous vehicles (AVs) is a concept that comes to mind. Technologies related to AVs are vehicles automation, automation, and electrification of public transportation, and electric propulsion [53]. Moreover, the term smart home is becoming more relevant, implying the use of cloud servers, cloud learning services, and machine-learning algorithms. Besides, a home service robot must be capable of recognizing human body activity, tracking a human position, sound-based human activity monitoring, and fall detection and rescue [54]. Assistive robots can also be used as caregivers in smart homes for elderly people [55]. Context awareness is an important topic related to surveillance. To achieve a context-aware model applied to an intelligent surveillance robot, techniques such as data mining, Bayesian network, collaborative filtering, and machine learning are applied [56]. People's economy is an important topic to consider; therefore, the development of financial technology (FinTech) supported by AI is vital for the world's economy [57]. Self-service technologies (SSTs) such as automated teller

machines, self-checkouts, and self-service kiosks are likely to use and implement service robots with human-like characteristics such as memory, gaze, and gestures [58].

As shown below, the principal technologies related to service robots are artificial intelligence, the Internet of Things, human recognition, machine learning, blockchain, and big data. Table 1 states and summarizes some keywords used by authors.


**Table 1.** Operation areas, applications, and keywords related to service robots.

#### *3.3. Commercial Technology*

Currently, the technology level in service robots is emerging; that is, the technology started to be commercialized by some vendors. Industry leaders have pilots and deployments in commercial service robots such as SoftBank Robotics, Furhat Robotics, Smart Robotics, and Temi. From a consumer perspective point of view, this level of maturity implies the very first generation of products, a very high price, and customization. Accordingly, a few firms dominate personal service robots, mainly taken by vacuum cleaners such as iRobot, approximating the market as an oligopoly.

Within the global market, there are different items of service robots, with some sample commercial robots presented in Table 2. There are applications on logistic, defense, public environmental, medical, field, exoskeletons, construction, inspection and maintenance, professional cleaning, and other uses. It is essential to mention that, for the most part, from 2018 to 2020, the sales of each item doubled. Moreover, the sales value of professional services robots has increased by 32%, which means 11.2 billion USD from 2018 to 2019 (data taken from EMIS). Furthermore, the COVID-19 pandemic can potentiate this growth. Robotic disinfection solutions, robotic logistics solutions in factories and warehouses, or robots for home delivery are examples of this trend, according to the World Robotics 2020—Service Robots report, presented by the International Federation of Robotics (IFR).

A significant sector that is currently adopting service robots is the hotel sector. As presented in [59], there exists a correlation in positive online reviews of hotel services to the use of service robots, and it also happens to increase the motivation of guests to write a review providing evidence of the service given by the robot. Another example of early commercial adoption of this technology is the catering and delivery business. According to [60], malls and university campus cafeterias are adopting delivery robots in order to reduce queue lines, thus reducing the mean delivery time. Such a study demonstrates an increase in business profit up to 95.4% when implementing the so-called Contactless Meal Order and Takeout Service (MOTS).

However, as of today, in 2021, market researchers, [61], have studied the relationship between the perception of value in consumers and users of service robots. A categorization presents the relative value of the robot as hedonic or utilitarian (hedonic refers to the value that enters via emotion or feelings, utilitarian value refers to value selected via rational behavior or monetary value) in different aspects such as hotels, hospitals, airports, and other tourism activities. The cited study throws two important conclusions: the utilitarian value is essential to obtain customers, and the hedonic value will attract more clients and *catch the eye* of the new possible users. Such values prompt a design guideline in the future of service robots. The following main conclusion suggests that, at the current stage, users are unlikely to pay attention to the utilitarian value of service robots. However, the more engaged society is with this kind of robot, the more likely it will increase actual utilitarian value.

The perceived responsibility in case of malfunction of a service robot triggers another pitfall when developing commercial technology. The work by [62] calculates the *degree of responsibility* in the errors that happen on the robot end and on the user end. The results happen to be inconsistent with the self-serving bias [63], which states that people attribute their successes but not the failures. In the study context, the adverse outcomes (errors and undesirable situations) are attributed to the service customer/user, and positive outcomes are attributed to the service robot.


**Table 2.** Sample commercial service robots.


**Table 2.** *Cont*.

#### *3.4. Scientific Literature*

Due to the rapid advances in robot technology combined with AI, the creation and implementation of service robots in different industrial sectors have increased dramatically. Service robots can be in different forms; they can be virtual, chatbots, humanoids, and non-humanoids [61]. Thanks to the advances in robotics and the implementation of AI, machines can perform even more complex and repetitive tasks [59].

Some AI and natural language processing applications emerged as a COVID-19 response to protect and prevent further damage due to the health crisis that emerged in 2020. An example of this technology implementation is the Intelligent Voice Assistant for Coronavirus Disease Self-Assessment, a deployment that successfully merges natural language processing and cloud computing to create a virtual service robot that helps to diagnose symptoms related to COVID-19 [71].

The demand for service robots grew for the attention of social distancing and healthmonitoring protocols due to the COVID-19 outbreak. Therefore, many industries have opted to include service robots as part of their staff to improve customer experience, service quality, and efficiency, as well as to reduce labor costs [72]. For example, service robots can provide more accurate services reducing mistakes and becoming more reliable and consistent than human employees. More importantly, robots can perform tasks without stopping, at a faster pace than humans, as well as carry multiple, repetitive, and mundane tasks without protesting [72].

Human–robot interaction is in constant development; the acceptance of service robots has flourished. To illustrate this idea, Figure 6 shows a prediction of the near future on the potential development of service robots. However, since it still is an early stage of development of the service robots, some groups of persons are open to their use, while others express concerns related to the negative consequences [61].

The recent and fast development of robotic technologies has inspired tourist corporations to adopt service robots. An excellent example of this is the service robot "Pepper". The benefits of this adoption were a noticeable increase in the customer's satisfaction, as well as creating a positive word-of-mouth [73]. For instance, medical robot assistants are being used to monitor patients and alert the medical staff when needed. Nowadays, the implementation of robotic medical assistants has increased due to the COVID-19 outbreak, resulting in a valuable and efficient way to monitor and control highly contagious diseases patients [74].

An exploratory study reveals that service robots are becoming a popular and more recurrent feature in tourism. This study suggests the tourism market perceives implementation of service robots as valuable, not only for interested technological visitors but also by an increasing number of customers [59]. Other studies have implemented service robots in restaurant companies to reduce work hours and improve service quality. The restaurant industry suffers from product losses constantly when the total demand exceeds the service production capacity. Results demonstrate the robots have reduced 20 work hours of the service staff, also improving labor productivity (sales per hour) and reducing

the losses dramatically due to lack of production; with the implementation of service robots, the service production sustained a higher and more efficient pace [75]. Current robotics applications will be covered in the next section. Moreover, we wondered about the terms associated with our search, so we constructed two different word clouds. One including single keywords used by the authors in the reviewed papers (see Figure 7) and one including composed keywords (see Figure 8).

Potential Development of Service Robots

for Personal Use

**Figure 6.** Service robots potential development for personal/domestic use.

**Figure 7.** Word cloud of simple keywords used by authors in the reviewed literature.

**Figure 8.** Word cloud of composite keywords used by authors in the reviewed literature.

#### *3.5. Applications*

There are several applications where service robots can add value; due to their versatility, the different needs of each industry will lead the design process.

A new frontier entering the market in industrial robotics are new, easy-to-use collaborative robotics solutions, where the robot advantages such as precision, speed, and

repeatability come together with the flexibility and cognitive skills of human workers [76]. In the past years, industrial robots were robust, used to perform a specific task, and placed into a cage for the safety of others. However, collaborative robots are designed and prepared to interact and work alongside humans [77].

Recently, the development of collaborative industrial robots for the manufacturing process has increased. There are automatic guided vehicles (AGVs), as observed in Figure 9, that are a type of service robots whose primary functionality is to help in the realization of internal transport processes [78]. Another application is the human–robot interaction (HRI), which is becoming a new trend thanks to technology and advances in perception, cognition, and control algorithms. As interest in these robots increases, so do the benefits of their implementation, such as productivity and production line flexibility [79], resulting in increased production and demand from industries to integrate them [80].

A significant application for service robots is daily-life assistance. It is very complex because, for comfortable assistance, the robot must recognize its surroundings, including the motion of humans, the position of the objects, and obstacles such as stairs [81]. The principal objective in this application is to reach effective communication between the robot, its real-world environment, and the people in it [82]. In such a situation, the robot must have a manipulator that can grasp, transport, and place objects, as these are fundamental capabilities for this type of service robot [83].

**Figure 9.** Example of AGV robots [78].

A robot-integrated smart home (RiSH) refers to a house that contains at least one service robot, a sensor network, a mobile device, cloud servers, and remote caregivers [54], so the service robot controls everything inside the house from afar. A telepresence robot system performs assistive functions to improve the well-being of elderly persons. It can assist them to do daily activities independently, to encourage social interactions to combat the sense of isolation or loneliness, and to help the professional caregivers in routine care [84]. However, in this scope, it is crucial to consider the acceptance of service robots by elderly people considering the psychological variables for proper interaction between people and technology [85].

Another application where service robots are being incorporated and are considered the workforce of the future is in operation and management, including the hotel industry [86]. In this case, a bellboy robot performs hotel-related functions such as walking alongside guests and providing information about the city and the hotel [87]. Depending on these functionalities and the total interaction with hotel guests, the overall experience of the visitors will change [88].

In recent years, the primary purpose of developing more robots has been to improve productivity. However, with the current COVID-19 pandemic, a more urgent purpose has arrived [89] where robots present significant advantages. We have been involved in the revolutionary development of mobile healthcare robots as there is a need for people to avoid physical interaction [38]. It enables the closer analysis of this need in order to ensure the regulation of social distancing rules [90].

Hand gestures will be the usual method to manipulate human–computer interfaces (HCIs); however, to assist people with motor disabilities, an HCI must be designed especially for them. The help of service robot platforms in communication with threedimensional (3D) imaging sensors and a wearable armband explores this solution [91].

As technology advances, society must adapt to new trends. Therefore, students and teachers have incorporated some of the latest technologies, overcoming many obstacles in the process. One of these technologies is the NAO humanoid robot that is currently being used in computer and science classes from elementary schools to university classes in many countries around the world [92].

Regarding business and financial institutions, there has already been considerable progress automating specific tasks implementing RPA and RPM concepts. As an example, Vodafone combines RPA and RPM to identify non-standard orders that require a high level of human interaction, which helps to reduce the time invested into checking complex orders before delivering to a supplier [93]. In the banking industry, some cases using RPA are: automatic report generation, opening an account, audit and compliance, chatbots, anti-money laundering, among others [94]. The combination of RPA and IA can lead to improved operational efficiency and increase the impact on the economics of innovation. However, RPA implementation is limited to business and banking; industries such as insurance, manufacturing, logistics, government, and public security can also take advantage of this technology [95], thus, it is of utmost importance to determine the current degree of automation in an organization's business processes to correctly identify tasks and processes that can be automated or improved [96]. RPA is an emerging technology that will have many applications, but one of the critical challenges to fully take advantage of this technology is to transfer digital tasks (performed in an environment with a virtual desktop interface) to cyber-physical tasks and processes [97].

Service robots can navigate through inaccessible or unsafe environments for the Urban Search and Rescue (USAR), where human teams cannot enter. The principal features that these types of robots must have are speed, weight, robustness, reliability, affordability, adaptability to different environments or tasks, and provide excellent two-way audio and/or video communication [98]. As well as the shown applications in the previous section, service robots have become a significant worldwide trend. The following section covers some robotics trends.
