Chemically and mechanically robust SWCNT based strain sensor with monotonous piezoresistive response for infrastructure monitoring

The application of stretchable strain sensors in civil and structural engineering involving infrastructural monitoring has become the hot subject of research. However, their imperative performance in infrastructure monitoring is often hindered by environmental conditions particularly, underwater and corrosive environments. Herein, we report the facile fabrication of chemically and mechanically stable strain sensor based on oxidized SWCNT (ox-SWCNT) and polydimethylsiloxane (PDMS). The strong molecular level interaction of ox-SWCNT and PDMS provides sensitive piezoresistivity. Applied strain to the fabricated sensor results in highly synchronized resistive response in large strain range of 100%, demonstrating one to one correspondence (monotonous response) in resistance-strain behavior. Most importantly, the protruding structure of ox-SWCNT covered with low surface energy PDMS provides in-situ resiliency, not only towards water but also to acidic and alkaline solution. Its high durability under abrasive situations illustrates the potential applicability in real time infrastructure monitoring under harsh conditions.