Protein-Based Flexible Conductive Aerogels for Piezoresistive Pressure Sensors

Abstract

Gelatin is an excellent gelling agent and is widely employed for hydrogel formation. Because of the poor mechanical properties of gelatin when dry, gelatin-aerogels are comparatively rare. Herein we demonstrate that protein nanofibrils can be employed to improve the mechanical properties of gelatin aerogels, and the materials can moreover be functionalized with a an electrically conductive polyelectrolyte resulting in formation of an elastic electrically conductive aerogel that can be employed as a piezoresistive pressure sensor. The aerogel sensor shows a good linear relationship in a wide pressure range (1.8–300 kPa) with a sensitivity of 1.8 kPa –1 . This work presents a convenient way to produce electrically conductive elastic aerogels from low-cost protein precursors.

Cellulose Nanofibers/PEDOT:PSS Conductive Aerogel for Pressure Sensing Prepared by a Facile Freeze-Drying Method

“…The main factor affecting the sensitivity of the aerogel at this time is the recovery after deformation. Its higher sensitivity in the range of 0–2 kPa is superior not only to carbon-based materials − but also to flexible substrates loaded with conductive fillers ,,− (Figure e).…”

Flexible resistive tactile pressure sensors

“…Copyright at Advanced Functional Materials, 2021 (g) protein nanofibers can be used to improve the mechanical properties of gelatin aerogels and increase their elasticity. 133 Reproduced with permission. Copyright at ACS Applied Bio Materials, 2022 (h) current-time (I-t) curves of the sensor when repeatedly applying and removing a weight corresponding to a pressure of 41.6 kPa (1000 cycles).…”

“…Copyright at ACS Applied Bio Materials, 2022 (h) current-time (I-t) curves of the sensor when repeatedly applying and removing a weight corresponding to a pressure of 41.6 kPa (1000 cycles). 133 Reproduced with permission. Copyright at ACS Applied Bio Materials, 2022 (i) average sensitivity of five independently prepared LPNF : GEL : PEDOT-S (2.7 : 8 : 1) aerogels.…”

“…Copyright at ACS Applied Bio Materials, 2022 (i) average sensitivity of five independently prepared LPNF : GEL : PEDOT-S (2.7 : 8 : 1) aerogels. 133 Reproduced with permission. Copyright at ACS Applied Bio Materials, 2022.…”

Lightweight and Mechanically Robust MXene/Polyimide/Silver Nanowire Composite Aerogels for Flexible Piezoresistive Sensors

“…The composite aerogel shows excellent electrical conductivity, and its applications in piezoresistive sensors have been demonstrated (the sensitivity is 0.18 kPa –1 when the compressive stress is within 0–1.5 kPa). In addition, other conductive materials, such as various metal nanowires, − polypyrrole, polythiophene, and so on, have also been used for preparing the aerogel piezoresistive sensors. Although many aerogel piezoresistive sensors have been reported, it remains a challenge to realize aerogel piezoresistive sensors with high linear sensitivity in a wide stress range.…”