50 million tons of electronics are expected to be trashed this year, according to a United Nations Environment Program report. A Stanford University team was concerned over the escalating epidemic of e-waste, so they created a semiconductor – a component in most of our electronics – that can actually be broken down with a weak acid such as vinegar.
Nine Stanford researchers, joined by one scientist from Hewlett Packard Labs and two engineers from the University of California, Santa Barbara, set out to rethink electronics. Engineer Zhenan Bao, who heads up the Bao Research Group at Stanford, said they found inspiration from human skin. Skin stretches, can heal itself, and is ultimately biodegradable. The researchers wanted to take these characteristics and apply them to electronics.
They created a flexible polymer able to decompose. Postdoctoral fellow Ting Lei said it’s the first ever “semiconductive polymer that can decompose.” But that’s just one part of a semiconductor. The team also designed a degradable electronic circuit and a biodegradable substrate material.
They used iron – a nontoxic, environmentally friendly product – instead of the gold usually used for electronic components. They made a paper-like substrate with cellulose; the transparent substrate allows the semiconductor to adhere to rough or smooth surfaces, like onto an avocado as seen in the picture above or on human skin. The semiconductor could even be implanted inside a body. According to Stanford, “When the electronic device is no longer needed, the whole thing can biodegrade into nontoxic components.”
The team envisions a number of uses for their semiconductors, like in wearable electronics. They could be made into patches allowing people to track their blood pressure, for example, or could be dropped via plane into a forest to survey the landscape, and eventually they would biodegrade instead of littering the environment.
The journal Proceedings of the National Academy of Sciences of the United States of America published the research online the beginning of May.
Images via Stanford University/Bao lab