Unprocessed Aloe Vera Gel as Quasi-Solid-State Electrolyte for High-Performance Organic Electrochemical Transistors

Area of Science:

• Materials Science
• Electrochemistry
• Biotechnology

Background:

• Organic electrochemical transistors (OECTs) demand electrolytes with high ionic conductivity, mechanical flexibility, biocompatibility, and sustainability.
• Conventional electrolytes like aqueous solutions, ionic liquids, and synthetic hydrogels struggle to meet all these requirements simultaneously.

Purpose of the Study:

• To investigate the potential of natural aloe vera gel as a single-component quasi-solid electrolyte for OECTs.
• To evaluate the performance of OECTs utilizing aloe vera gel as the gating medium.

Main Methods:

• Rheological testing to characterize the gel's viscoelastic properties.
• Electrical measurements to determine ionic conductivity and interfacial capacitance.
• Fabrication and testing of OECT devices using aloe vera gel as the electrolyte.

Main Results:

• Aloe vera gel exhibits a soft, viscoelastic network with an ionic conductivity of ~6.1 mS/cm and interfacial capacitance of ~58.5 μF/cm².
• OECTs with aloe vera gel achieved high performance, including a peak transconductance of ~11 mS and an ON-current of ~6.5 mA, comparable to phosphate buffered saline (PBS).
• The devices demonstrated rapid switching kinetics and excellent stability, retaining over 96% of drain current after 100 cycles.

Conclusions:

• Natural aloe vera gel is a viable, high-performance electrolyte for OECTs.
• It offers a unique combination of biocompatibility, biodegradability, and excellent electrochemical properties.
• This finding supports the development of sustainable and "green" bioelectronic systems.