**1. Introduction**

The micro-electro-mechanical system (MEMS) is a process technology comprising of miniaturized mechanical and electronic parts, that includes the transformation of a measured mechanic signal into a readable signal. This signal may be force, pressure, heat, or chemical. MEMS has created serious innovations in micro- and nano-study fields since the early 1980s [1]. Primarily, MEMS has been improved for different implementations for example force, navigation, optical transmitting, radio frequency, biological and medical, microfluidics, and gyroscope applications [2–6]. Currently, MEMS has become an essential part of various study fields such as material, mechanical, and electrical engineering studies [7–9]. The MEMS device is usually formed of four components, micro-structures, micro-sensors, micro-actuators, and micro-electronics for data utilization [10,11].

MEMS technologies have been manufactured by traditional methods such as lithography, galvano forming, and photolithography etc. These methods are dependent on additive or subtractive procedures that operate minuscule capacities of materials in the shape of thin layers on the surface of silicon wafers [12–16]. These conventional techniques are extremely precise and appropriate for the production of planar geometries [17]. Although precise, these operations are associated with some drawbacks such as multiple processing steps, the requirement of a cleanroom, an advanced work environment, lengthy fabrication, inconsistency of flexible materials, and a costly fabrication process [18]. With the improvement of 3D printing-additive manufacturing, the fabrication costs and processing steps of MEMS devices have been gradually reduced. According to these improvements, it is possible to fabricate MEMS devices in atmospheric air without the need for multiple operations and cleanrooms [19,20]. Due to such advantages, it is now possible to use 3D printing technology for micro beam fabrication.

3D printing technology has become progressively popular in the fabrication of MEMS, since it can be employed to manufacture complicated structures clearly from digital files, for instance computer-assisted design drawings. This technology helps to improve the design and production and especially facilitates the production and repair of complex parts using printing through layer- by-layer deposition of the constituent materials [21–23]. With the progress of 3D printing techniques, interest in using 3D printing for building MEMS systems has grown remarkably in the areas of biomedical, electronics, wearable devices, soft robots, and automotive applications [24–29]. Unlike traditional manufacturing processes such as machining and punching, 3D printing does not entail on-site process control, cutting tools, coolers, or other additional resources. One of the important factors of 3D printing methods is its capability to make miniaturized complex structural geometries using easy steps that are not achievable by traditional manufacturing methods. Besides that, 3D printing methods offer many other characteristics, for example flexibility in geometrical designs, excellent feature size and shapes, and the ability to print functionally classified materials [30,31].

Micro beams are utilized as important components of different sensing and actuation systems such as sensors, gyroscopes, micro actuators, and resonators [32–34]. Their easy geometries make them very advantageous in terms of design, and microfabrication. In many applications, ranging from residual stress measurement mass flow sensors to biomedical or DNA analysis, the sensing mechanism is linked to the sensitivity of the micro beam to some applied stimulation [35–37]. Many studies have been conducted, especially in the field of DNA [38–40]. In a study, a multi-scale analytical model was created to define the relationship between the surface mechanical features of DNA self-assembled 2D films and the detection signals of DNA-micro beam systems [41]. Micro beams exactly predict the dynamic properties of the device, such as its natural frequencies and forced- vibration response.

Fabrication methods are very significant in designing and researching micro beams. Until now, conventional MEMS fabrication methods have been used, such as photolithography and surface micromachining, etc. [42,43]. These methods are usually time-consuming, with high fabrication costs, and multi-step fabrication processing. Alternatively, the 3D printing or additive manufacturing method solves these problems by manufacturing the structure directly. In recent years, various 3D printing methods have been employed, for instance frontal polymerization (FP), projection microstereolithography (PµSL), laser micro sintering (LMS), selective laser melting (SLM), etc. [44–47]. Among the different 3D printing techniques, the digital light processing (DLP) technique using photocurable resins is appealing, since it can be used to manufacture a single layer of the 3D object through spatially-controlled solidification using a projector light [48]. This light produces benefits such as fast fabrication, high sensitivity, and surface quality. Besides, it is feasible to adapt the final features of the printed object by only altering the photocurable resin formulations [49]. In this way, it is feasible to reach a large diversity of systems for the fabrication of structures with excellent features and functions [50].

In this study, we present our development on utilization of DLP technology for fast and highly sensitive production of a micro beam with sub-millimeter scale properties. The DLP and PµSL methods were compared based on the fabrication results. With this study, a micro beam was fabricated for the first time using the 3D printing method. It is expected that this paper will contribute to the current literature in terms of manufacturing a micro device through the use and comparison of different techniques.

This study is arranged as follows. Section 2 describes the design of the micro beam. Section 3 explains the fabrication process, results, and discussion. Section 4 displays the result of the studies.

### **2. Materials and Methods**

### *2.1. Design Conditions*

The possibility of coupling thermal, electrical, and structural characterization by fabrication of a micro beam is accomplished with a model. For characterization, the displacement of the micro beam **2. Materials and Methods** 

is produced by passing a current through a beam; heat is produced by the current, and the rise in temperature causes a displacement through thermal expansion. The displacement of the micro beam is formed in these situations. is produced by passing a current through a beam; heat is produced by the current, and the rise in temperature causes a displacement through thermal expansion. The displacement of the micro beam is formed in these situations.

micro beam is accomplished with a model. For characterization, the displacement of the micro beam

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The MEMS-based micro beam is designed to move in one direction (*y*-axis). For the beam to move on the *y*-axis, DC voltage must be applied. The feet of the micro beam at both ends are rigidly bound to a substrate, and DC voltage is applied at both ends. The applied voltage induces an electric current in the micro beam; current passing through the structure causes some retardation to the free flow of electrons by which energy is dissipated in the form of heat. This generated heat induces thermal stress on the beam and displaces the beam. The dimensioning and geometric structure of the micro beam, designed as a 3D (3-dimensional plane) using CAD software, is shown in Figure 1. The MEMS-based micro beam is designed to move in one direction (*y*-axis). For the beam to move on the *y*-axis, DC voltage must be applied. The feet of the micro beam at both ends are rigidly bound to a substrate, and DC voltage is applied at both ends. The applied voltage induces an electric current in the micro beam; current passing through the structure causes some retardation to the free flow of electrons by which energy is dissipated in the form of heat. This generated heat induces thermal stress on the beam and displaces the beam. The dimensioning and geometric structure of the micro beam, designed as a 3D (3-dimensional plane) using CAD software, is shown in Figure 1.

**Figure 1.** Dimensions of the micro beam. **Figure 1.** Dimensions of the micro beam.

All the dimensions of our micro beam are shown in Table 1. These values were obtained with the measurements of the beam made with the DLP and PμSL methods. The same design was used for both methods. Nevertheless, as the supporting structures cannot be fabricated with the PμSL, the measurements concerning the support are shown in Section 3. Photopolymer materials were used for this study. These materials are frequently utilized in the field of MEMS because of their essential physical and electrical features. All the dimensions of our micro beam are shown in Table 1. These values were obtained with the measurements of the beam made with the DLP and PµSL methods. The same design was used for both methods. Nevertheless, as the supporting structures cannot be fabricated with the PµSL, the measurements concerning the support are shown in Section 3. Photopolymer materials were used for this study. These materials are frequently utilized in the field of MEMS because of their essential physical and electrical features.


**Table 1.** Description of the micro beam.
