3D printing of multiaxial force sensors using carbon nanotube (CNT)/thermoplastic polyurethane (TPU) filaments

Kim, Kyuyoung; Park, Jaeho; Suh, Ji Hoon; Kim, Min Seong; Jeong, Yongrok; Park, Inkyu

doi:10.1016/j.sna.2017.07.020

Cited by 268 publications

(171 citation statements)

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“…[241] with permission from the IEEE. Angewandte Chemie Reviews nanotubes (CNTs;F igure 9c) [246,247] or silver/silicone composite to be incorporated into haptic interfaces (Figure 9d). [248] Haptic interfaces in combination with additive manufacturing have also greatly improved general education and the education of the blind.…”

Section: Additive Manufacturing In Haptic Interfacesmentioning

confidence: 99%

Bio‐inspired Design and Additive Manufacturing of Soft Materials, Machines, Robots, and Haptic Interfaces

et al. 2019

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Soft materials possess several distinctive characteristics, such as controllable deformation, infinite degrees of freedom, and self‐assembly, which make them promising candidates for building soft machines, robots, and haptic interfaces. In this Review, we give an overview of recent advances in these areas, with an emphasis on two specific topics: bio‐inspired design and additive manufacturing. Biology is an abundant source of inspiration for functional materials and systems that mimic the function or mechanism of biological tissues, agents, and behaviors. Additive manufacturing has enabled the fabrication of materials and structures prevalent in biology, thereby leading to more‐capable soft robots and machines. We believe that bio‐inspired design and additive manufacturing have been, and will continue to be, important tools for the design of soft robots.

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Section: Additive Manufacturing In Haptic Interfacesmentioning

confidence: 99%

Bio‐inspired Design and Additive Manufacturing of Soft Materials, Machines, Robots, and Haptic Interfaces

et al. 2019

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“…Besides these material-specific variations, process-specific anisotropies in resistivity are also analyzed in several studies (see Table 1). Both factors of influence regarding geometry, e.g., build orientation [2,[22][23][24], and with regard to process are investigated, for instance, raster angle [1,2], raster width [21], air gap or flow rate [1,21] as well as active cooling [4], extrusion speed [4], and temperature [1,4]. In addition to electrical conductivity, Watschke et al (2017) [1] and Dul et al (2018) [2] investigated resistive heating due to process-and material-specific variations.…”

Section: Characterization Of Electrically Conductive Composite Materimentioning

confidence: 99%

“…The influence of electrical bonding on the resistivity is not part of the studies mentioned above; however, Kim et al (2017) [24] postulated the suitability of silver paste.…”

Section: Characterization Of Electrically Conductive Composite Materimentioning

confidence: 99%

Design and Characterization of Electrically Conductive Structures Additively Manufactured by Material Extrusion

2019

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Multi-material additive manufacturing offers new design freedom for functional integration and opens new possibilities in innovative part design, for instance, a local integration of electrically conductive structures or heat radiant surfaces. Detailed experimental investigations on materials with three different fillers (carbon black (CB), carbon nanotubes (CNT) and nano copper wires) were conducted to identify process-specific influencing factors on electrical conductivity and resistive heating. In this regard, raster angle orientation, extrusion temperature, speed and flow rate were investigated. A variation of the raster angle (0 • , ±45 • , and 90 • ) shows the highest influence on resistivity. An angle of 0 • had the lowest electrical resistance and the highest temperature increase due to resistive heating. The material filled with nano copper wires showed the highest electrical conductivity followed by the CNT filled material and materials filled with CB. Both current-voltage characteristics and voltage-dependent heat distribution of the surface temperature were determined by using a thermographic camera. The highest temperature increase was achieved by the CNT filled material. The materials filled with CB and nano copper wires showed increased electrical resistance depending on temperature. Based on the experiments, solution principles and design rules for additively manufactured electrically conductive structures are derived. Appl. Sci. 2019, 9, 779 2 of 25 or casting), the designer has entirely new opportunities in product design. Consequently, there are two big challenges. On the one hand, the design engineer needs to be supported to ensure a consideration of these new design potentials in conceptual design. On the other hand, rules for designing conductive structures have to be established, for instance, to adjust the electrical resistance. The latter research gap is focused on in this contribution. Therefore, a simultaneous consideration of part design and process planning is crucial to leverage the advantages of AM's design freedom [9]. A provision of specific knowledge regarding AM's design potentials is essential for both, conceptual design (e.g., solution principles) and detail design (e.g., design rules) [10]. At present, no systematic consideration of the design potentials of multi-material AM, especially regarding electrically conductive structures, in product development is possible. There are only rudimentary frameworks [11] or general design heuristics for multi-material AM [12,13]. Moreover, design rules for MEX generally concern only geometrical restrictions [14] or consider process related influencing factors on mechanical properties [15]. However, no specific guidelines and rules for the design of additively manufactured conductive structures have been developed. Consequently, designers have no common basis on which functions such as electrical conductivity or heat radiation can be integrated in multi-material parts manufactured by MEX.Extensive experimental investigations were condu...

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“…Furthermore, the majority of these methods could only prepare sensors with simple planar structures. However, macroscale structures are required for applications on sophisticated surfaces and multifunctional sensors . Hence, novel manufacturing methods are needed to address the challenges of mass production and diversified applications in the future.…”

Section: Introductionmentioning

confidence: 99%

Flexible Pressure Sensors with Wide Linearity Range and High Sensitivity Based on Selective Laser Sintering 3D Printing

Zhang

et al. 2019

Adv Materials Technologies

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applications in electronic skin (E-skin), human-machine interfaces, and healthcare monitoring. [1][2][3][4] Among the various types of sensors employing piezoresistive, [5][6][7] capacitive, [8][9][10] piezoelectric, [11][12][13] and triboelectric [14][15][16] sensing mechanisms, the piezoresistive mechanisms have been intensively investigated due to their high sensitivity, simple structures, easy fabrication, and convenient data processing, resulting in significantly promising commercialization prospects. [17][18][19] To achieve success in practical applications, excellent performances in the pressure range related to human activity and scalable, low-cost, and reproducible manufacturing processes are decidedly required. [20][21][22][23] Piezoresistive pressure sensors based on composite materials consisting of elastic matrixes and conductive fillers have been comprehensively investigated and adopted in commercial applications due to their good performance and compatibility with scalable printing technology. [3,21,24] However, the sensors based on bulk resistance changes generally exhibited poor sensitivity in low pressure ranges, which limited their applications in E-skin or wearable devices. To break the bottleneck, flexible pressure sensors composed of surface microstructures and conductive layers were proposed, in which the signals were typically generated from the variation of the contact resistance. [25,26] The transformed working mechanism greatly promoted the sensitivity up to 10-100 kPa −1 (especially in the low pressure range) and decreased the limit of detection (LOD) to 1 Pa or less. [26][27][28] Nonetheless, for plenty of microstructure-based sensors, the response ranges with high sensitivity were limited to several kPa since the contact areas of the microstructures were easily saturated under small pressure. First, the narrow range would limit their applications in the medium-pressure range [29,30] (10-100 kPa), which is closely related to daily human activity. Second, the background stress that is generated from nontest objects can easily disable a sensor with a narrow sensing range. [31,32] In addition to the sensing range, a linear relationship between the pressure and the electrical signals was typically desired to facilitate data processing. [21,33] Considering that the sensitivity was usually different in the whole range, the available range would be further narrowed down, which set To achieve practical applications of flexible pressure sensors, good performance and scalable manufacturing processes are both desired. Here, flexible pressure sensors with excellent performance are fabricated via selective laser sintering (SLS). Having benefitted from the irregular microstructures generated in the powder sintering process, the sensors exhibit high sensitivity of 55 kPa −1 in a wide linearity range of 100 kPa, and they maintain decent sensitivity (>10 kPa −1 ) over a high-pressure range (100-400 kPa), which is among the best results for flexible pressure sensors. The working mechanism of the sensor...

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3D printing of multiaxial force sensors using carbon nanotube (CNT)/thermoplastic polyurethane (TPU) filaments

Cited by 268 publications

References 30 publications

Bio‐inspired Design and Additive Manufacturing of Soft Materials, Machines, Robots, and Haptic Interfaces

Bio‐inspired Design and Additive Manufacturing of Soft Materials, Machines, Robots, and Haptic Interfaces

Design and Characterization of Electrically Conductive Structures Additively Manufactured by Material Extrusion

Flexible Pressure Sensors with Wide Linearity Range and High Sensitivity Based on Selective Laser Sintering 3D Printing

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