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Highly Morphology‐Controllable and Highly Sensitive Capacitive Tactile Sensor Based on Epidermis‐Dermis‐Inspired Interlocked Asymmetric‐Nanocone Arrays for Detection of Tiny Pressure
Author(s) -
Niu Hongsen,
Gao Song,
Yue Wenjing,
Li Yang,
Zhou Weijia,
Liu Hong
Publication year - 2020
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201904774
Subject(s) - materials science , capacitive sensing , tactile sensor , pressure sensor , nanoporous , nanotechnology , optoelectronics , capacitance , sensitivity (control systems) , computer science , electronic engineering , electrode , artificial intelligence , robot , operating system , chemistry , physics , engineering , thermodynamics
The tactile sensor lies at the heart of electronic skin and is of great importance in the development of flexible electronic devices. To date, it still remains a critical challenge to develop a large‐scale capacitive tactile sensor with high sensitivity and controllable morphology in an economical way. Inspired by the interlocked microridges between the epidermis and dermis, herein, a highly sensitive capacitive tactile sensor by creating interlocked asymmetric‐nanocones in poly(vinylidenefluoride‐ co ‐trifluoroethylene) film is proposed. Particularly, a facile method based on cone‐shaped nanoporous anodized aluminum oxide templates is proposed to cost‐effectively fabricate the highly ordered nanocones in a controllable manner and on a large scale. Finite‐element analysis reveals that under vertical forces, the strain/stress can be highly strengthened and localized at the contact apexes, resulting in an amplified variation of film permittivity and thickness. Benefiting from this, the developed tactile sensor presents several conspicuous features, including the maximum sensitivity (6.583 kPa −1 ) in the low pressure region (0–100 Pa), ultralow detection limit (≈3 Pa), rapid response/recovery time (48/36 ms), excellent stability and reproducibility (10 000 cycles). These salient merits enable the sensor to be successfully applied in a variety of applications including sign language gesture detection, spatial pressure mapping, Braille recognition, and physiological signal monitoring.