文部科学省大学間連携共同教育推進事業「未来像を自ら描く電気エネルギー分野における実践的人材の育成」
Ionically conducting (Iontronic) devices for next-generation soft sensors and actuators [3月2日（月） 福岡工業大学]
2018/02/14
【科目種別】電気エネルギー講座Ⅱ（英語科目）
■講 師： Dr. Yuta Dobashi
■ご所属： Advanced Materials and Process Engineering Laboratory,
Department of Electrical and Computer Engineering,
The University of British Columbia （カナダ）
■演 題： Ionically conducting (Iontronic) devices for next-generation soft sensors and actuators
■日 時： 平成 30年 3 月 2日（金）13:00～14：30
■場 所： 福岡工業大学 E棟3階 Cul Site R1
■主 催： 福岡工業大学 大学院工学研究科
■概要
As fields of wearable technologies, soft robotics, and bionics emerge, there is increasing interest in creating bendable and stretchable alternatives to conventional sensors and actuators. For example, recent work on soft and transparent dielectric elastomers has shown promise by demonstrating large-strain actuation as well as pressure sensing.
In this presentation, we take a look at ionically conducting polymers as a class of materials to use towards development of soft sensors and actuators. First, polyacrylamide hydrogel based capacitive sensor arrays are introduced, capable of detecting proximity and pressure even during bending and stretching. The polyacrylamide electrodes are embedded in silicone elastomer housing. These widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with 5-mm spacing. It is found that proximity of an object up to 2 cm above the array is readily detectable. Electrode capacitance changes of up to 15 % (with the baseline capacitance of approximately 2pF) were observed during proximity and light touch tests, which are sufficiently greater than background noise generated by bending or stretching. Conventional touch screen gestures such as swipe, multi-finger touch are successfully demonstrated.
The second type of sensor (Piezoionic sensor) uses the effect where aqueous hydrogels or other organic polyelectrolytes undergoing mechanical deformation results in mechanically driven ion transport. This ion transport typically is inhomogeneous due to the difference in ionic transport number, and create a net charge separation. This, unlike the first approach, is a self-generating property of the gel requiring no external driving energy, and may also be highly analogous to human mechanoreceptors. The charge output of the Piezoionic sensors is evaluated, and their possible applications as an artificial mechanoreceptor are explored.
Third approach to iontronic sensing is based on electrical double layers (EDL). We demonstrate a device using a droplet of water between two Indium Tin Oxide (ITO) electrodes with one electrode being coated with poly[4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole-co-tetrafluoroethylene] (PTFE-AF). We investigate its frequency response up to 100 Hz, surpassing literature’s best, with a maximum peak-to-peak voltage of 892 mV. We present a linear approximation model that can be used for further optimization of such a system and correctly predicts the point of maximum power transfer, enabling evaluation of the system as both a sensor and generator in its current state and ideas that could make this technology competitive.
The above approaches show that iontronic devices are becoming a viable option to play important roles in the development of next-generation soft robotics and bionic systems.
■講 師： Dr. Yuta Dobashi
■ご所属： Advanced Materials and Process Engineering Laboratory,
Department of Electrical and Computer Engineering,
The University of British Columbia （カナダ）
■演 題： Ionically conducting (Iontronic) devices for next-generation soft sensors and actuators
■日 時： 平成 30年 3 月 2日（金）13:00～14：30
■場 所： 福岡工業大学 E棟3階 Cul Site R1
■主 催： 福岡工業大学 大学院工学研究科
■概要
As fields of wearable technologies, soft robotics, and bionics emerge, there is increasing interest in creating bendable and stretchable alternatives to conventional sensors and actuators. For example, recent work on soft and transparent dielectric elastomers has shown promise by demonstrating large-strain actuation as well as pressure sensing.
In this presentation, we take a look at ionically conducting polymers as a class of materials to use towards development of soft sensors and actuators. First, polyacrylamide hydrogel based capacitive sensor arrays are introduced, capable of detecting proximity and pressure even during bending and stretching. The polyacrylamide electrodes are embedded in silicone elastomer housing. These widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with 5-mm spacing. It is found that proximity of an object up to 2 cm above the array is readily detectable. Electrode capacitance changes of up to 15 % (with the baseline capacitance of approximately 2pF) were observed during proximity and light touch tests, which are sufficiently greater than background noise generated by bending or stretching. Conventional touch screen gestures such as swipe, multi-finger touch are successfully demonstrated.
The second type of sensor (Piezoionic sensor) uses the effect where aqueous hydrogels or other organic polyelectrolytes undergoing mechanical deformation results in mechanically driven ion transport. This ion transport typically is inhomogeneous due to the difference in ionic transport number, and create a net charge separation. This, unlike the first approach, is a self-generating property of the gel requiring no external driving energy, and may also be highly analogous to human mechanoreceptors. The charge output of the Piezoionic sensors is evaluated, and their possible applications as an artificial mechanoreceptor are explored.
Third approach to iontronic sensing is based on electrical double layers (EDL). We demonstrate a device using a droplet of water between two Indium Tin Oxide (ITO) electrodes with one electrode being coated with poly[4,5-difluoro-2,2-bis(trifluoromethyl)-1,3-dioxole-co-tetrafluoroethylene] (PTFE-AF). We investigate its frequency response up to 100 Hz, surpassing literature’s best, with a maximum peak-to-peak voltage of 892 mV. We present a linear approximation model that can be used for further optimization of such a system and correctly predicts the point of maximum power transfer, enabling evaluation of the system as both a sensor and generator in its current state and ideas that could make this technology competitive.
The above approaches show that iontronic devices are becoming a viable option to play important roles in the development of next-generation soft robotics and bionic systems.
