Highly Conductive Liquid Metal-Based Shape Memory Material with an Ultrasensitive Fire Warning Response

Fire warning materials always play an important role in safeguarding people's lives and property. In general, existing approaches to realize supersensitive fire warning responses are typically focused on how to reduce response times. However, most strategies to effectively achieve fire warning require a high trigger temperature of over 180 °C that is unsuitable for fire warning of materials with a low flash point. Herein, a liquid metal-based shape memory material (LM-SMM) is fabricated by integrating liquid metal (LM), polydimethylsiloxane (PDMS), and polyurethane foam. The phase transition function of the LM contributes to better shape fixation properties. Meanwhile, the flexibility of PDMS assures good shape recovery performance. In particular, the LM-SMM still owns favorable electrical conductivity that could facilitate its application in advanced electronics. The combination of switchable structure and excellent electrical conductivity makes this LM-SMM appropriate for an ultrasensitive fire warning response. With the help of such performance, the LM-SMM can achieve the lowest fire-warning response temperature in a fast response time, which displays promising application in the safe storage of flammable materials. More importantly, this work could not only achieve the fabrication of highly conductive LM-SMM but also expand applications, thus providing possibilities for the next-generation supersensitive fire-warning response materials.