Flexible strain/pressure sensor with good sensitivity and broad detection range by coupling PDMS and carbon nanocapsules

The high sensitivity and broad detection range for flexible sensors are desirable but remains a big challenge. Herein, we developed a novel multi-level porous structure of polydimethylsiloxane/carbon nanocapsules composite (PDMS/CNCs) through a facile template method to combine the high sensitivity sensor with broad detection range. The multi-level porous structure consists of nano-scale hollow pores of CNCs and the larger micro-scale pores generated from the template removal. Integrating the excellent conductivity and mechanical properties of CNCs and superior toughness and flexibility of PDMS, the flexible sensor exhibits a positive resistance change under a broad pressure detection range from 0 to 450 kPa. This heavy load pressure sensing capacity exploit a new application in the field of security and protection by equipping carpet with our sensors to spot intruders. Meanwhile, corresponding to stretching and bending deformation, the sensor also possesses highly sensitive strain response of 150.7 and 20.11, respectively. Furthermore, the practical application of our sensor for meticulously detecting the human being joints bending is confirmed without disturbing the normal activities of the human body. The designing high-performance sensors with multi-level pores and high flexibility make it easy for the ultrahigh displacement sensitivity and broad pressure detection range.