A hydrogel sensor based on conic baston structure

Abstract

Resistive flexible pressure sensors are extensively employed in wearable devices owing to their wide operational range and straightforward construction. This study presents a conic bastion-structured sensor microunit to improve the sensor sensitivity. The base hydrogel is synthesized using acrylamide (AM), with Mg²⁺ and Na⁺ acting as conductive ions. The sensor is fabricated using digital light processing (DLP) 3D printing technology and is subjected to experimental evaluation. The findings indicate that the hydrogel sensor with a 50 wt% AM composition demonstrates enhanced mechanical strength and conductive properties, achieving a peak sensitivity of 0.534 kPa⁻¹ within a pressure range of 0–0.8 kPa. Furthermore, the sensor exhibits favorable response characteristics (30 ms) and recovery characteristics (40 ms), along with stability. The proposed sensor is suitable for wearable devices and live joint angle detection. Additionally, the “handwriting fingerprint” pattern recognition and document verification proposed in this article make it applicable in scenarios, such as banking, notarization, and other handwriting and seal verification contexts.