Glycine-Chitosan-Based Flexible Biodegradable Piezoelectric Pressure Sensor

Area of Science:

• Materials Science
• Biomaterials Engineering
• Nanotechnology

Background:

• Development of sustainable and biodegradable materials is crucial for reducing electronic waste.
• Piezoelectric materials are essential for various sensor applications, including pressure sensing.
• Existing piezoelectric materials often lack biodegradability and biocompatibility.

Purpose of the Study:

• To fabricate and characterize flexible, free-standing piezoelectric films using glycine and chitosan.
• To evaluate the potential of these biodegradable films as pressure sensors for biomedical applications.
• To confirm the formation of the ferroelectric phase of glycine within the chitosan matrix.

Main Methods:

• Self-assembly of glycine molecules within a water-based chitosan solution.
• Fabrication of piezoelectric films using a solvent-casting method.
• Characterization of film structure using X-ray diffraction (XRD).
• Evaluation of piezoelectric properties, including sensitivity, capacitance, dielectric constant, and loss factor.

Main Results:

• Formation of a stable spherulite structure of β-glycine embedded in amorphous chitosan.
• Confirmation of the pure ferroelectric phase of β-glycine via XRD.
• Achieved piezoelectric sensitivity of ~2.82 ± 0.2 mV kPa⁻¹, comparable to non-biodegradable materials.
• Measured capacitance ranging from 0.26 to 0.12 nF (100 Hz–1 MHz), with a dielectric constant of 7.7 and loss factor of 0.18.

Conclusions:

• The glycine-chitosan composite is a promising bio-based piezoelectric material.
• The developed films are suitable for creating biodegradable pressure sensors.
• Potential applications include wearable biomedical diagnostics and sustainable electronic devices.