Biodegradable, Flexible and Transparent Tactile Pressure Sensor Based on Rubber Leaf Skeletons
Anastasia Koivikko, Vilma Lampinen, Kyriacos Yiannacou, Vipul Sharma, Veikko Sariola
Abstract
Capacitive sensors have many applications in tactile sensing, human-machine interfaces, on-body sensors, and patient monitoring. Particularly in biomedical applications, it would be beneficial if the sensor is disposable and readily degradable for efficient recycling. In this study, we report a biodegradable capacitive tactile pressure sensor based on sustainable and bio resourced materials. Silver-nanowire-coated rubber tree leaf skeletons are used as transparent and flexible electrodes while a biodegradable clear tape is used as the dielectric layer. The fabricated sensor is sensitive and can respond to low pressures (7.9 mN when pressed with a probe with a surface area of 79 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> / 0.1 kPa) ranging to relatively high pressures (37 kPa), with a sensitivity up to <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\approx \,\,4.5\times 10 ^{-3}$ </tex-math></inline-formula> kPa <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−1</sup> . Owing to all bio resourced constituents, the sensor is biodegradable and does not create electronic waste.