Flexible Piezoresistive Tactile Sensor Based on Polymeric Nanocomposites with Grid-Type Microstructure

Area of Science:

• Materials Science
• Nanotechnology
• Sensor Technology

Background:

• Piezoresistive tactile sensors utilize nanocomposite polymeric materials for flexibility and sensitivity.
• Improving low-pressure sensing performance requires uniform filler dispersion and effective structural design.

Purpose of the Study:

• To develop a novel flexible piezoresistive tactile sensor with enhanced performance.
• To optimize sensor design, specifically the grid-type microstructure and filler material concentration.

Main Methods:

• Fabrication of flexible tactile sensors using polydimethylsiloxane (PDMS) matrix and multi-walled carbon nanotubes (MWCNTs) filler.
• Systematic variation of MWCNT doping (1-10 wt.%) and optimization of grid structure dimensions (line width, spacing, thickness).
• Characterization of sensor performance, including sensitivity, response range, repeatability, and stability under varying environmental conditions.

Main Results:

• A 7 wt.% MWCNT doping with a 1 mm grid structure showed high sensitivity (6.821 kPa⁻¹ at 10-20 kPa).
• Optimized grid dimensions (1 mm width, 1 mm spacing, 0.5 mm thickness) yielded improved sensitivity (0.2704 kPa⁻¹ at 50-130 kPa).
• The sensor demonstrated stable, repeatable responses, unaffected by temperature and humidity, with minimal error fluctuation (5.6%) and fast response time (1.6 ms).

Conclusions:

• The developed piezoresistive tactile sensor, based on MWCNT/PDMS nanocomposites and optimized grid microstructure, offers significant improvements in sensitivity and stability.
• The sensor's performance is tunable via dopant concentration and structural design, primarily influenced by quantum tunneling effects.
• The proposed tactile sensor exhibits practical feasibility for diverse applications in wearable technology and robotics, including touch detection and grasping.