Conductive Hydrogel-Based Grip Pressure Measuring Device for Hand Rehabilitation

Abstract

This study introduces a novel grip pressure measuring device for hand rehabilitation, utilizing a 2-hydroxyethyl acrylate (2-HEA)-based conductive hydrogel. The hydrogel, fabricated through a UV-initiated 3D printing process, demonstrates robust mechanical properties, including a Young's modulus of 44.8±8.0 kPa and high fatigue resistance, making it suitable for repeated deformation. Electrical properties were evaluated by an impedance analyzer achieving a sensitivity of 8.54 kΩ when the hydrogel is deformed by 1%. The device incorporates a unique air-chamber design and a four-probe method for precise resistance measurement, with signals processed via custom electronics. Experimental validation, involving a real-time graphical pressure control task, confirmed the accuracy and usability of the device. This hydrogel-based sensor offers a promising tool for advanced rehabilitation monitoring and control, particularly for detecting low-pressure variations, which are essential for early-stage rehabilitation or certain neuromuscular conditions.