Direct Ink Writing of Silicone Elastomer Composites as Wearable Strain Sensor: From Materials to Applications for Physiological Health Monitoring

Abstract

ABSTRACT Silicone elastomer composites (SECs), owing to their tunable functionalities, represent a class of ink materials with immense potential for the design and development of wearable sensors through 3D printing technologies. This review reports recent advances in SEC‐based strain sensors printed through direct ink writing techniques, focusing on ink formulation and design strategies to improve sensor performance for health monitoring applications. The aim is to provide crucial information for the development of 3D‐printed sensors, from materials to manufacturing. The techniques for ink formulations to produce polymer composites and compliant electrodes are discussed, with consideration of filler‐matrix interactions. Thereby, strategies to improve sensitivity by varying the structural design and electrode patterning schemes are explored, required to preserve signal integrity under dynamic strain conditions. Lastly, various strain sensors demonstrated for physiological health monitoring are included to recognize the work directed in improving linearity, sensing range, response time, durability, etc. This work contributes to the pathways from ink preparation to sensor fabrication with high precision using printing technologies.