Stretchable Sensors


Soft conductive materials change their electrical resistance and capacitance when they are deformed. These characteristics can be used for sensors that can detect deformations. Highly stretchable sensors are useful in systems that undergo large deformations such as soft robots and wearable devices.


Self-sensing McKibben artificial muscles embedded with dielectric elastomer sensor


Integration a thin capacitive sensor into a McKibben artificial muscle has made it possible to detect the amount of expansion and contraction. Since the sensor can be added using a simple process, this method has the advantage of simplifying the structure of the resulting self-sensing artificial muscle. The model built in parallel showed good agreement with the experimental data, indicating that it is possible to design the sensor response.

Ryo Kanno, Shuya Watanabe, Keita Shimizu, and Jun Shintake, "Self-Sensing McKibben Artificial Muscles Embedded With Dielectric Elastomer Sensor." IEEE Robotics and Automation Letters, 6 (2021) : 6274


Artificial muscle with and without sleeve (top) and the cross-sectional view (bottom)


Sensitivity improvement of highly stretchable capacitive strain sensors by hierarchical auxetic structures


Highly stretchable capacitive strain sensors have several advantages compared to those based on resistive sensing. On the other hand, the sensitivity of capacitive type sensors are generally low. To address this issue, we have proposed to integrate auxetic structures with the sensors. Auxetic structures have a negative Poisson's ratio that allows to mechanically program the deformation of the devices such that their sensitivity is enhanced. The result shows that the sensitivity is improved by a factor of two compared to sensors with a normal configuration.

Jun Shintake, Toshiaki Nagai, and Keita Ogishima. "Sensitivity Improvement of Highly Stretchable Capacitive Strain Sensors by Hierarchical Auxetic Structures." Frontiers in Robotics and AI 6 (2019): 127.
新竹純,荻島啓太,永井敏輝,静電容量型ソフト歪みセンサの感度向上,Dynamics and Design Conference, 361, 2019.


Deformation of the highly stretchable capacitive strain sensor integrated with an auxetic structure