MXene-based self-adhesive, ultrasensitive, highly tough flexible hydrogel pressure sensors for motion monitoring and robotic tactile sensing

Abstract

With the rapid development of artificial intelligence and human–computer interaction fields, wearable electronic devices represented by flexible pressure sensors have a wider range of application scenarios. In this paper, we used a composite hydrogel made by one-pot polymerization using a combination of acrylamide (AM), sodium carboxymethyl cellulose (CMC), dopamine (DA), and MXene (Ti3C2Tx). The composite hydrogel has the advantages of self-adhesion, high sensitivity, large detection range (0–500 kPa), low detection limit, high toughness (compression > 90 %), stability (more than 6700 s) and other advantages of hydrogel flexible pressure strain sensor. Sodium carboxymethyl cellulose (CMC), as a multifunctional thickener and gelling agent, significantly improves rheological properties and viscosity in hydrogels, forms crosslinked structures to enhance mechanical properties and provides reliable toughness for pressure sensors. Dopamine (DA), which is rich in catechol groups, can adhere to the material surface through oxidative polymerization to enhance bond strength. Hydrogel pressure sensors for human motion detection can accurately track joint movement, respond sensitively to changes in knocks and touches, and display specific characters such as Morse code. The technology extends to robotic systems, where pressure-activated electrical signals are used to control robot movements. Therefore, it has a very promising application in the field of human–computer interaction, human-body movement signal detection, etc. PAM/CMC/DA/MXene hydrogel pressure sensors have excellent mechanical, electrical, and adhesion properties, which provide a more reliable solution for the fields of flexible wearable e-skin, human–computer interaction, and tactile sensing.