Bioinspired Engineering of Fillable Gradient Structure into Flexible Capacitive Pressure Sensor Toward Ultra‐High Sensitivity and Wide Working Range

Abstract

Tactile sensing is required for electronic skin and intelligent robots to function properly. However, the dielectric layer's poor structural compressibility in conventional pressure sensors results in a limited pressure sensing range and low sensitivity. To solve this issue, a flexible pressure sensor with a crocodile‐inspired fillable gradient structure is provided. The fillable gradient structure and grooves in the pressure sensor accommodate the deformed microstructure that permits the enhancement of the media layer compressibility via COMSOL finite element simulation and optimization. The pressure sensor exhibits a high sensitivity of up to 0.97 k Pa−1 (0–4 kPa), a wide pressure detection range (7 Pa–380 kPa), and outstanding repeatability. The sensor can detect Morse code, robotic grabbing, and human motion monitoring. As a result, flexible sensors with a bionic fillable gradient structure pave the way for wearable devices and offer a novel method for achieving highly precise tactile perception.

Simple fabrication of high-sensitivity capacitive tactile sensor based on a polydimethylsiloxane dielectric layer using a biomimetic gray kangaroo leg structure

“…Researchers and developers are already actively investigating tactile sensors due to their ease of access to acquisition data and applicability to applications. Tactile sensors are mainly classified into four sensing mechanisms: capacitive [16][17][18][19][20], piezoresistive [21][22][23][24], piezoelectric [25][26][27], and triboelectric [28][29][30], among which capacitive tactile sensors with a simplified structure, easy signal acquisition, and low-power consumption have become a research hotspot for researchers [31].…”

Bamboo-Inspired, Environmental Friendly PDMS/Plant Fiber Composites-Based Capacitive Flexible Pressure Sensors by Origami for Human–Machine Interaction

“…With the need for booming developments in the fields of flexible wearable devices, − smart healthcare, − human–computer interaction, − electronic skin, − and smart electro-textiles (e-textiles), , persistent studies on flexible electronic devices , have become more urgent and indispensable. Flexible electronic devices are flexible, thin low-cost, and have adjustable mechanical properties.…”

A Flexible Capacitive Pressure Sensor with Adjustable Detection Range Based on the Inflatable Dielectric Layer for Human–Computer Interaction

“…Through the above research, it has been found that the range of the sensor has been greatly improved, but the sensor cannot better adapt to different scene requirements in different pressure ranges. So, wide range flexible pressure sensors are still a research difficulty and there is a great demand in practical applications. − Meanwhile, most existing pressure sensors are designed for specific application scenarios, and their sensing range and corresponding sensitivity are often immutable, making them unable to flexibly adapt to different load applications. − Therefore, designing a capacitive pressure sensor with a simple structure, wide detection range, better performance trade-off and flexibility is of great value to better meet different needs in practical applications and avoid replacing sensors with different ranges.…”