Ultraflexible, High-Performance Transistors and Logic Circuits on Biocompatible Polylactic Acid (PLA) Substrate

Area of Science:

• Materials Science
• Electronics Engineering
• Biomedical Engineering

Background:

• Wearable and implantable devices are crucial for smart healthcare and human-machine interfaces.
• Biocompatible flexible materials are needed for advanced electronic devices.
• Polylactic acid (PLA) offers biodegradability, cost-effectiveness, and low immunogenicity.

Purpose of the Study:

• To fabricate high-quality polylactic acid (PLA) thin films using a solution-based spin-coating method.
• To develop thin-film transistors (TFTs) on PLA substrates at low temperatures (<40 °C).
• To investigate the electrical characteristics and mechanical stability of PLA-TFTs and construct logic circuits.

Main Methods:

• Solution-based spin-coating for PLA thin film fabrication.
• Fabrication of Indium Gallium Zinc Oxide (IGZO) channel, Silicon Dioxide (SiO2) dielectric, and Indium Tin Oxide (ITO) gate/source/drain electrodes using shadow masking.
• Low-temperature processing (<40 °C).

Main Results:

• PLA-TFTs exhibited excellent flexibility, biocompatibility, and electrical properties.
• Achieved charge carrier mobility of 27.81 cm²/(V s), subthreshold swing of 162.8 mV/decade, and ON/OFF current ratio of 1 × 10Â⁶.
• Demonstrated stable performance under various deformations and successful fabrication of AND, OR, and NOT logic gates.

Conclusions:

• PLA is a suitable biocompatible flexible substrate for fabricating high-performance TFTs.
• The developed low-temperature fabrication process enables complex logic circuits on flexible materials.
• Findings support the advancement of intricate logic circuits and functionalities in smart healthcare and human-machine interfaces.