Entropy-driven silicone rubber composite with reversible actuation and fire safety for hydrothermal-independent strain sensors

Document Type

Article

Publication Date

6-15-2025

Abstract

Two-way shape-memory polymers (2W-SMPs) are a type of intelligent polymers and show great potential applications in many fields, such as soft robotics, actuators, and sensors. However, existing 2W-SMPs are polymer networks with low crosslinking density, which exhibit severe creep, narrow operating temperature range, and high fire hazards, resulting in low dimensional stability and poor actuation accuracy as sensors and actuators. To mitigate these problems, we designed an entropy-driven and highly cross-linked flexible silicone rubber/SiO2 composite (CSR/SiO2). High crosslink density endows the CSR/SiO2 with low creep and high actuation reversibility. Good ductility ensures the CSR/SiO2 have good two-way shape memory effect (2W-SME). The thermal stability, hydrophobicity, and good flame retardancy of silicone rubber give the CSR/SiO2 a wide operating temperature range for 2W-SME with high fire safety and moisture stability. Elastic and thermal entropy change has been identified as the mechanism driving the 2W-SME. The test results show that the CSR/SiO2 exhibits 100 % actuation reversibility at an operating temperature from room temperature up to 200 °C, a tunable linear coefficient of thermal expansion from −8.13 × 10−4 to 2.12 × 10−4 °C−1, and UL-94 V0 vertical burning rating. In addition, the CSR/SiO2 has been demonstrated as potential substrates for wearable electronics in structural health monitoring, from engineering structures such as airplane and bridge to human body, which are subjected to hydrothermal stresses in addition to external load induced stresses. This work provides a new strategy for designing novel 2W-SMPs.

Publication Source (Journal or Book title)

Chemical Engineering Journal

This document is currently not available here.

Share

COinS