Transparent curved transistor fabrication opens door to combined sensing and imaging

Nanotechnologists at Oregon State University’s College of engineering have developed a way of fabricating transparent transistors onto sharply curved surfaces, building on research to develop glucose sensors that can be wrapped around a tube. Although the research was originally directed towards diabetes treatments, and these may be an important application for the technique, it has potential for many other medical applications.

The original research was intended to manufacture a catheter that could be inserted into the bloodstream of a diabetic patient to continuously measure glucose levels. These could then be used to determine the appropriate dose of insulin to be delivered from a pump: effectively, an artificial pancreas. Greg Herman and Xialsong Du had fabricated glucose sensors onto a flat polymer film that was then wrapped around the catheter. In testing, however, the sensors tended to detach from the film, or the film appeal of the catheter.

In their new research, Herman and Du turned to a different method for fabricating sensors: microcontact printing, which uses relief patterns of a “master stamp”, usually made from a soft elastomeric polymer such as polydiimethylsiloxane, to form patterns of layers of ink on a substrate. They use this technique to print amorphous indium gallium zinc oxide field-effect transistors (a-IGZO-FET)  directly onto glass tubes with a 1mm radius. They describe the research in a paper in the journal Sensors and Actuators B: Chemical.