According to researchers, the problem stems from researchers not distinguishing between the behavior of the sensor material and the electrical contacts. “A lot of scientists misunderstand their sensor response because they lump together the behavior of the contacts with the behavior of the sensor material,” said Matthew Grayson, a professor of electrical and computer engineering at Northwestern’s McCormick School of Engineering, in a statement.
The researchers achieved stronger and more reliable electrical contact by sanding down this insulating layer. They also developed a calibration method to measure the thickness of the layer both electrically and microscopically, offering a new troubleshooting approach that other researchers can follow.