Fast and precise tongue pressure measurement by intraoral laser-induced graphene pressure sensor for elderly healthcare

Abstract

Tongue pressure (TP) monitoring is essential for evaluating oral functions and improving elderly healthcare, particularly in addressing challenges related to chewing, swallowing, and speech. However, commercial balloon-based TP sensors have limitations in large footprints, small linear response ranges, and practical challenges in durability and replacement. Here, we introduce a novel TP sensor based on laser-induced graphene (LIG), fabricated through direct laser writing. This sensor is designed to provide a smaller footprint, higher linearity, enhanced durability, and simpler maintenance for advanced elderly healthcare. LIG patterns were generated on polyimide films by direct irradiation of ultraviolet (UV) nanosecond laser pulses and transferred onto biocompatible polydimethylsiloxane (PDMS) substrates. The sensor was encapsulated with an additional thin layer of PDMS to protect the oral environment. The fabricated TP sensor demonstrated exceptional sensitivity of 0.00594 kPa-1 across a wide pressure range (1-300 kPa), with rapid response times and long-term cyclic robustness. In-vivo tests validated its reliable and precise TP monitoring capability, proving its effectiveness in practical uses. Our approach paves a way for 3D-printed smart dentures for advanced elderly care while also offering broader applications in oral rehabilitation and biomechanical human-aid devices for general body pressure sensing.