Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE This study presents a multifunctional PVA/CPBA/CMC@PANI hydrogel made via a simple one-pot method, embedding CMC@PANI microspheres in a dual-crosslinked network. It exhibits excellent mechanical properties, self-healing ability, and conductivity, enabling dual-responsive strain and temperature sensing for wearable health monitoring and smart devices.

ABSTRACT
Conductive hydrogels are promising for flexible wearable sensors due to their flexibility, conductivity, and sensing capabilities. Herein, a multifunctional polyvinyl alcohol/4-carboxyphenylboronic acid/carboxymethyl cellulose@polyaniline hydrogel is fabricated by embedding spherical carboxymethyl cellulose@polyaniline microspheres into a PVA/4-carboxyphenylboronic acid hydrogel. The synergistic effect of borate and hydrogen bonds forms a dynamic dual-crosslinking network, endowing the hydrogel with high tensile strength (0.31 MPa), excellent stretchability (1415%), fast self-healing ability, and good conductivity (3.57 S m−1). Notably, the engineered hydrogel is assembled as a dual-responsive sensor, exhibiting strain and temperature sensing for wearable electronics and healthcare monitoring applications. As a strain sensor, it showed good sensitivity (gauge factor: 1.88), fast response/recovery time (about 200 ms), and cyclic stability, allowing accurate detection of joint movements and facial expressions. As a temperature sensor, its temperature-sensing capability relies on the synergistic effect of the dynamic rearrangement of borate (BOC) bonds and hydrogen bonds, PANI's temperature-dependent conductivity, and ionic mobility. Thus, it exhibits a negative temperature coefficient of resistance (TCR = −1.52%/°C) in the temperature range of 20°C–60°C, enabling continuous body temperature monitoring and detection of febrile states. This work provides a general strategy for self-healing dual-responsive sensor hydrogels for wearable electronics in healthcare and human-robot interfaces.