Saurabh Bhooshan Mishra supervised by Dr. Aftab M Hussain received his Master of Science  in Electronics and Communication Engineering (ECE). Here’s a summary of his research work on Fabrication of Soft Pressure Sensor using Chemical Synthesis:

Flexible pressure sensors based on conductive polymers and porous dielectric materials are gaining significant attention for applications in wearable devices, human-machine interaction, and soft robotics. In this work, we present the fabrication and characterization of flexible pressure sensors using polypyrrole-coated cotton textile (PCC) and bubble-induced PDMS foam. A highly compressible multilayer capacitive pressure sensor was developed using PDMS foam as the dielectric layer and PCC as the electrodes. The PDMS foam was prepared by mixing specific amounts of ethanol into PDMS, and the electrodes were attached using silicone adhesive. The fabricated sensor demonstrated low hysteresis, high repeatability, and good step response. Surface profiling and scanning electron microscopy were used to characterize the bubble structure. Applications such as mouse click detection and grasping objects with varying weights were demonstrated, highlighting the sensor’s versatility for free-form electronics. Additionally, an ultra-soft capacitive pressure sensor was developed using polyurethane foam with polypyrrole-coated surfaces as electrodes. Various concentrations of pyrrole and FeCl3 were used to optimize the sensor performance, achieving a high sensitivity of 1.01 kPa−1 at 25 kPa pressure. Finite element simulations were performed to study mechanical deformation and space charge variations under pressure. This sensor also offers customizable shapes and sizes for diverse applications. Further, a piezoresistive pressure sensor was fabricated using PCC synthesized via in-situ chemical oxidative polymerization. This sensor exhibited high sensitivity in the low-pressure range of 160 Pa to 16 kPa and a response time of 463 ms. It showed excellent repeatability over 1000 loading unloading cycles, with a gauge factor of 0.32 for compressive strains up to 99.6%, enabled by the fibrous structure of cotton. Finally, a large area flexible conductive cotton fabric (20 cm ×20 cm) was fabricated using in-situ polymerization of polypyrrole. The fabric maintained stable conductivity after multiple washing cycles, with resistance changes stabilizing after the fourth wash. This demonstrates its potential in interactive textiles and smart fabric applications. 

August 2025