Peelable circuits can connect almost anything

Researchers have developed peelable electronic circuits that can connect almost anything to the IoT

The Internet of Things (IoT) is expanding rapidly. By 2020 there will be an estimated almost 31 billion connected devices worldwide. At Springwise, we have already seen smart devices as diverse as coffee cups, appliances, clothing and bicycle lights. As the number of connected devices grows, the technology that enables these objects to communicate will need to become quicker, cheaper and easier to manufacture and use. Researchers at Purdue University and the University of Virginia are working toward this goal. They have developed tiny, thin-film electronic circuits that users can stick on and later peel off of surfaces.

The technique developed by the team eliminates several manufacturing steps, which lowers production costs. The stickers also allow almost any object to turn into a connected object instantly. The researchers developed a fabrication technique called ‘transfer printing’. Ordinary designs build electronic circuits on a silicon ‘wafer’ and remove them using high temperatures and chemical etching. This damages the wafer, so each circuit needs a new one. The new method applies the circuit to the wafer as a thin film. A metal layer, such as nickel, lies between the electronic film and the silicon wafer. When submerged in water, the film is easy to peel off the wafer, so the wafer is reusable.

The thin-film electronic circuits can be trimmed and pasted onto any surface, granting that object has electronic features. This makes the uses for the peelable circuits almost endless. Chi Hwan Lee, Purdue assistant professor of biomedical and mechanical engineering suggested that, “We could customise a sensor, stick it onto a drone, and send the drone to dangerous areas to detect gas leaks, for example.” The stickers could potentially also sense temperature changes and then stick to flowerpots to let people know when they need to water the plants.