Multifunctional starch-based conductive hydrogels for smart sensors and flexible supercapacitors

Area of Science:

• Materials Science
• Polymer Chemistry
• Nanotechnology

Background:

• Developing environmentally tolerant and recyclable hydrogels is crucial for harsh working conditions and eco-friendly demands.
• Existing hydrogels often lack the stability and conductivity required for advanced applications.

Purpose of the Study:

• To construct a multifunctional conductive hydrogel by incorporating starch into a polyvinyl alcohol (PVA)/glycerin (Gly)/lithium chloride (LiCl) matrix.
• To evaluate the hydrogel's properties, including conductivity, anti-freezing capabilities, stability, and performance in sensors and supercapacitors.

Main Methods:

• Synthesized a starch-based conductive hydrogel (PSGL) using PVA, Gly, and LiCl.
• Characterized hydrogel properties: conductivity, anti-freezing, dehydration resistance, and recycling stability.
• Investigated the mechanism of Gly and LiCl using density functional theory (DFT) simulations.
• Fabricated and tested hydrogel-based sensors and supercapacitors.

Main Results:

• PSGL hydrogel achieved high conductivity (40.65 mS cm⁻¹) and excellent anti-freezing properties (-40 °C).
• Demonstrated remarkable stability: 82.6% weight retention after 30 days and 80% conductivity retention after recycling.
• Hydrogel sensors showed high sensitivity (GF = 1.68) and accurately detected human motion, enabling human-computer interaction via IoT.
• Supercapacitors exhibited a specific capacitance of 120.0 mF cm⁻² with 98.17% retention after 10,000 cycles.

Conclusions:

• The developed PSGL hydrogel offers a promising material for flexible electronics, soft robotics, and energy storage due to its multifunctionality and environmental tolerance.
• The study provides insights into hydrogel design for extreme environments and highlights the potential of starch-based materials.