A bio-inspired cilia array as the dielectric layer for flexible capacitive pressure sensors with high sensitivity and a broad detection range

Abstract

A cilia array via a magnetic field was proposed as the dielectric layer for flexible capacitive sensors with high sensitivity and a broad detection range.

Flexible and Stretchable Capacitive Sensors with Different Microstructures

“…[115,117] Zhou et al prepared a pressure sensor with cilia arrays imitating the human epidermis by embedding AgNWs into PDMS, which could be used for speech recognition (Figure 3G) and airflow monitoring (Figure 3H), expanding the application range of the sensor. [116] Although the output pressure capacitance curve of this device remains linear in the range of 0-12 kPa, the data showed nonlinearity in the range of 0-200 kPa. This feature is similar to the nonlinear mechanical behavior of human skin, [3] however, which is unfavorable to the deformation degree of the object, thereby limiting the application of sensors with microneedle structures.…”

Microstructured capacitive sensor with broad detection range and long-term stability for human activity detection

“…To date, researchers have made lots of efforts to improve the comprehensive performance of the capacitive sensor in various aspects, such as sensitivity, detection limit/range, response time, and stability 12,[22][23][24] . For example, introducing the microstructure has been regarded as one of the effective strategies for remarkably improving the sensor sensitivity due to the distinct deformation of the microstructure and the subsequent increase in the capacitance variation.…”

Natural bamboo leaves as dielectric layers for flexible capacitive pressure sensors with adjustable sensitivity and a broad detection range

“…The vibration of Adam's apple from the pronunciation can bring pressure to the sensor to change the output of capacitance signals. 28 When the volunteer spoke the words 'Wuyi' and 'University' three times and the phrase 'Wuyi University' once, the distinct capacitance changes and different patterns of signals were observed (Fig. 5f).…”

“…[18][19][20][21][22][23][24][25] Furthermore, the fabrication of a regular or irregular microstructure of the elastomeric electrode or dielectric layer is also adopted to improve the sensitivity and the related performance of the sensor. 5,[26][27][28][29][30][31][32][33] Park et al combined the superiority of the two concepts, developing a capacitive sensor with a porous pyramid dielectric layer. The assembled sensor showed a high sensitivity of 44.5 kPa À1 within the range of fewer than 100 Pa. 19 However, the construction of the porous structure or microstructure generally requires complicated and expensive approaches, such as photolithography, chemical etching, curing, and pre-stretching/UV exposure.…”