Implantable anti-biofouling biosupercapacitor with high energy performance

Area of Science:

• Biomedical Engineering
• Materials Science
• Energy Storage

Background:

• Biofluidic supercapacitors are promising for implantable electronics but face challenges with low energy storage in bioelectrolytes and biofouling.
• Existing supercapacitors suffer performance degradation due to biofouling, limiting their practical application in biological environments.

Purpose of the Study:

• To develop a high-performance, flexible biofluidic supercapacitor with enhanced energy density and anti-biofouling properties for implantable devices.
• To address the limitations of energy storage and biofouling in supercapacitors operating within biological fluids.

Main Methods:

• Fabrication of a flexible polydopamine (PDA)-infiltrated carbon nanotube (CNT) yarn (PDA/CNT) supercapacitor.
• Encapsulation of the PDA/CNT electrode within a hydrogel-barrier circular knit for anti-biofouling protection.
• In vitro and in vivo testing of the supercapacitor's energy storage performance, stability, and biofouling resistance.

Main Results:

• The PDA/CNT supercapacitor achieved a 250-fold increase in energy density compared to pristine CNT in biofluid.
• Demonstrated high areal capacitance (503.91 mF cm⁻²), energy density (274 μWh/cm²), and power density (25.52 mW cm⁻²).
• Showcased excellent stability with negligible capacitance loss after 10,000 cycles and bending tests, and maintained stable in vivo performance for 21 days without biofouling in a rat model.

Conclusions:

• The PDA/CNT supercapacitor offers a viable solution for high-performance, stable energy storage in biofluidic applications.
• The hydrogel-barrier encapsulation effectively prevents biofouling, ensuring long-term operational integrity of implantable supercapacitors.
• Successfully demonstrated in vivo energy storage and powering of a light-emitting diode, highlighting its potential for biomedical applications.