Ambipolar Bulk Heterojunction Semiconductor Fibers for High-Performance Neuromorphic Systems.

Area of Science:

• Materials Science
• Organic Electronics
• Bioelectronics

Background:

• Semiconductor fibers are key for flexible, wearable bioelectronic systems.
• Current unipolar fibers have limitations in integrated multifunctional applications due to charge transport restrictions.
• Advances in p- and n-type organic semiconductor fibers enable complementary organic electrochemical transistors (OECTs).

Purpose of the Study:

• To fabricate ambipolar bulk heterojunction (BHJ) semiconductor fibers.
• To overcome the limitations of unipolar fibers for advanced bioelectronic applications.
• To demonstrate the potential of BHJ fibers in neuromorphic computing and fiber-based bioelectronics.

Main Methods:

• Fabrication of ambipolar BHJ semiconductor fibers using a scalable wet-spinning process.
• Blending of p- and n-type conjugated polymers under controlled conditions.
• Characterization of fiber transport properties and fabrication of OECTs, logic circuits, and organic electrochemical neurons (OECNs).

Main Results:

• Optimized BHJ fibers exhibited balanced ambipolar transport with high mobility × volumetric capacitance (μC*) values.
• Achieved μC* values of 0.81 ± 0.09 F cm⁻¹ V⁻¹ s⁻¹ (n-type) and 0.63 ± 0.05 F cm⁻¹ V⁻¹ s⁻¹ (p-type) in OECTs.
• Demonstrated complementary logic circuits and OECNs with over 83% accuracy in sleep state recognition.

Conclusions:

• BHJ semiconductor fibers offer a promising platform for integrated neuromorphic computing.
• The developed fibers enable multifunctional, fiber-based bioelectronic systems.
• Scalable fabrication and balanced charge transport open new avenues for intelligent textiles and advanced sensors.