Printable Epsilon-Type Structure Transistor Arrays with Highly Reliable Physical Unclonable Functions

Area of Science:

• Electronics
• Materials Science
• Cybersecurity

Background:

• Printed electronics enable low-cost, large-area fabrication of devices on unconventional substrates.
• Secure communication and authentication are crucial for data-intensive printed electronic technologies.
• Physical unclonable functions (PUFs) offer hardware security by leveraging device-specific manufacturing variations.

Purpose of the Study:

• To develop high-reliability PUFs for printed electronics.
• To enhance the robustness of printed PUFs against environmental noise.
• To investigate novel structures for improved PUF performance.

Main Methods:

• Fabrication of printable epsilon-type indium tin oxide transistor arrays.
• Modification of the coffee-ring structure to enhance printing uncertainty.
• Utilizing print-induced variations in channel thickness and length for PUF construction.

Main Results:

• The epsilon-type structure improved printing scalability, film quality, and device reliability.
• Print-induced uncertainty in channel dimensions significantly increased.
• The developed PUFs demonstrated near-ideal uniformity, uniqueness, randomness, and reliability.
• PUFs showed resilience against machine-learning attacks with low prediction accuracy (55% without postprocessing).

Conclusions:

• Printable epsilon-type transistor arrays with modified coffee-ring structures are effective for creating high-reliability PUFs.
• This approach addresses the challenge of robustness in printed PUFs.
• The developed PUFs offer a promising solution for secure hardware in printed electronics.