Study on Highly Sensitive Capacitive Pressure Sensor Based on Silk Fibroin-Lignin Nanoparticles Hydrogel

Area of Science:

• Materials Science
• Biomaterials Engineering
• Nanotechnology

Background:

• Silk fibroin (SF) hydrogels show promise for pressure sensors but require performance enhancement.
• Developing flexible hydrogels from natural materials is an active area of research.

Purpose of the Study:

• To improve the sensing performance of silk fibroin hydrogels for pressure sensor applications.
• To investigate the effect of incorporating lignin nanoparticles (LNPs) into SF hydrogels.

Main Methods:

• A flexible hydrogel was prepared using natural macromolecular materials.
• Lignin nanoparticles (LNPs) were introduced during the preparation of the SF hydrogel.
• The sensing performance of the SF-LNPs hydrogel was evaluated.

Main Results:

• The SF-LNPs hydrogel with 3% LNPs (SF-LNPs_3%) exhibited high stress sensitivity (1.32 kPa^-1).
• The sensor demonstrated a fast response speed (<0.1 s) and superior cycle stability (≥8000 cycles).
• The hydrogel sensor successfully detected human motion (finger/elbow bending, pulse) and vocal cord signals.

Conclusions:

• The SF-LNPs_3% hydrogel offers significantly enhanced sensitivity and stability for pressure sensing.
• This material shows great potential for flexible electronic devices, particularly in motion and physiological signal detection.