Thermal-Driven Shape Memory Phase Change Materials for Potential Application in Shape Adaptable Microelectronic Devices

Abstract

Phase change materials (PCMs) that can effectively improve the efficiency of energy storage and conversion have been used in the field of microelectronic devices for prolonging service life. However, conventional PCMs are easy to cause brittle fractures and damage to microelectronic devices because of their strong rigidity, which cannot perfectly fit the irregular surface of microelectronic devices. Herein, we successfully synthesized a dynamic covalently cross-linked shape memory PCM (HPCM8K) with polyethylene glycol (PEG) as the phase change component, hexamethylene diisocyanate trimer as the crosslinking point, and a disulfide bond as the dynamic covalent bond. The tensile strength and the elongation at break of the designed HPCM8K-1 can reach 27.7 MPa and 853.1%, respectively; meanwhile, HPCM8K has excellent latent heat storage capacity with the highest latent heat of 98.1 J/g. Importantly, these HPCM8K can integrate both traditional elastic shape memory and permanent shape reconstruction capabilities into one PEG-based dynamic cross-linking network after introducing the disulfide bond in the molecular structure. The key point of this work is to introduce exceptional mechanical performance and remarkable shape memory ability into PCMs, greatly improving the operability of shape change and enhancing their shape adaptability for accommodating different surfaces of microelectronic devices.