Smart Self-Powered System Based on Supramolecular Conductive Hydrogel for Assistive Elderly Living

Abstract

Accelerated aging of the population has led to an increase in the incidence of orthopedic chronic diseases and acute illness, which has placed a significant burden on the public health and economy. Continuous physiological monitoring and timely rehabilitation interventions represent crucial strategies for early disease detection, functional independence preservation, and healthcare cost containment among elderly individuals. This study proposes a single-electrode triboelectric nanogenerator (PE-TENG) for elderly assistance systems, developed through the integration of a supramolecular conductive hydrogel (PCBC-hydrogel) with a soft Ecoflex layer. The PCBC-hydrogel, engineered from poly(vinyl alcohol) (PVA), chitosan, borate cross-linking, and carbon nanotubes (CNTs), serves as an advanced friction electrode material that combines mechanical compliance with stable electrical performance, making it particularly suitable for aging-care applications. The pristine PVA hydrogel showed moderate mechanical properties. Boric acid formed dynamic borate bonds with PVA hydroxyls, enhancing the elasticity and strength. Material characterization reveals that dynamic borate ester bonding between boric acid and PVA hydroxyl groups enhances mechanical resilience, achieving a tensile strength of ∼209 kPa. The introduction of chitosan facilitates additional hydrogen bonding networks, enabling rapid self-recovery within 10 s. Incorporated CNTs provide stable electrical conductivity (0.13 S/m) while reinforcing the hydrogel matrix. The PE-TENG demonstrates reliable operation with a 90 s response time and maintains a consistent performance through 3000 cycles. This design allows for real-time monitoring of physiological signals through mechanoelectrical transduction. The utilization of supramolecular hydrogel TENG-based health monitoring systems, smart home assistance systems, and bionic effector systems enables the real-time monitoring of the physical condition of the elderly, facilitating the promotion of their healthy lifestyles through the monitoring of the home environment and bionic control. This work not only promotes the development of hydrogel-based TENGs and provides another direction for self-powered wearable devices but also establishes a foundation for future smart aging-care systems.