The air-gap PAD: a roll-to-roll-compatible fabrication method for paper microfluidics

Area of Science:

• Materials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Paper-based analytical devices (PADs) offer accessible point-of-use testing but lack scalable fabrication methods.
• Commercial unavailability of wax printers necessitates alternative manufacturing techniques for PADs.

Purpose of the Study:

• To introduce and evaluate air-gap PADs as a scalable fabrication alternative.
• To compare the performance of air-gap PADs with traditional wax-printed PADs.
• To demonstrate the feasibility of large-scale manufacturing using roll-to-roll equipment.

Main Methods:

• Design considerations for air-gap PADs were investigated.
• Performance was evaluated through Washburn flow experiments, paper-based titration, and pharmaceutical screening.
• Pilot-scale roll-to-roll production was conducted in collaboration with a commercial manufacturer.

Main Results:

• Air-gap PADs demonstrated comparable performance to wax-printed PADs across various tests.
• Roll-to-roll manufacturing achieved a production of 2700 feet of air-gap PADs.
• The cost per air-gap PAD was as low as $0.03.

Conclusions:

• Air-gap PADs present a viable, scalable, and cost-effective alternative for fabricating paper-based analytical devices.
• Compatibility with roll-to-roll manufacturing facilitates mass production for widespread adoption.
• This technology holds significant potential for advancing accessible diagnostics and testing solutions.