Simultaneously encapsulation and formation of PDMS-MWCNTs composites for multidirectional microchannel force sensors

Abstract

Microchannel force sensors have good stretching characteristics and have garnered a lot of interest in the research area of health monitoring and human movement identification. However, there are still existing a number of problems for such microchannel-based force sensors, such as costly and time-consuming manufacturing procedures, layer mechanical mismatches, and poor instability. Here, we propose a flexible microchannel-based polydimethylsiloxane (PDMS)-multiwalled carbon nanotubes (MWCNTs) composite sensor with high sensitivity and directional stretching response. MWCNTs are inserted into microchannels using the self-diffusion approach, and a unique encapsulating process has been demonstrated that combines MWCNTs with PDMS to create a composite that maximizes interlayer mechanical compatibility. When compared to traditional encapsulation techniques, the novel encapsulating approach tenfold boosts the sensors’ sensitivity within the same pressure detection range. In the range of 0–100 kPa, the sensitivity is up to 0.0433 kPa−1, detecting pressures as low as 11.9 pa, while the gauge factor is as high as 18.1. The results demonstrate that the proposed microchannel force sensor has significant promise for the future in the field of motion detection, health monitoring, and so on.