Crosslinking‐Modulated Hydrogel Piezoionic Senor for Pattern Security Authentication in Human‐Machine Interfaces
writer：YueSun,GuoTian,TaoYang,ShenglongWang,BolingLan,XuelanLi,TianpeiXu,LongJin,WeiliDeng,*andWeiqingYang*
keywords：crosslinking degree, human-machine interfaces, piezoionic effect, response time, tactile sensor
source：期刊
Issue time：2024年
Ionic hydrogels are uniquely suited as force-sensing layers because of
their good biocompatibility and controlled electromechanical properties. The
emerging piezoionic effect allows them to sense the position of pressure, but
the low response rate limits their applications. Herein, this work focuses on
modulating the response time of piezoionic outputs through crosslinking. The
underlying mechanism is investigated through the perspective of deformation
recovery rate and ion migration behavior in the ionic hydrogels. As a result, the
developed piezoionic sensors are capable of distinguishing static forces in the
range of 0.1–5 s while monitoring dynamic force, breaking the limitations of
conventional self-powered pressure sensors that have trouble tracking static
forces. Furthermore, by utilizing the piezoionic effect to convert the touch
indentation into transverse gradient ionic potential, the constructed piezoionic
sensors achieve accurate monitoring of finger pressing position and sliding
trajectory. As a proof-of-concept, pattern unlocking in security authentication
is successfully validated based on the developed piezoionic sensors. This
design strategy of modulating ionic tactile sensor by crosslinking is expected
to provide a fresh path for the large-scale flexible human-machine interfaces.