Stretchy, Degradable Semiconductors Are the Future of Everything – Popular Mechanics

Adapted from ACS Central Science 2019, DOI: 10.1021/acscentsci.9b00850

In the future, diagnosing conditions inside your body might be as effortless as dissolvable stitches. Scientists from five different departments at Stanford have developed a stretchable semiconductor material that naturally dissolves in environments like the human body. The paper, shared through EurekAlert, details the teams development of a skin-inspired semiconductor made of a stretchy, acid-soluble semiconductor core with a similarly stretchy, biodegradable core.

So-called skin-inspired materials are the major rage in materials science because of the multiple kinds of engineering and design challenges they can alleviate. In their paper, the Stanford scientists say a skin-inspired material is more strain-tolerant, easier to fabricate, and could help reduce form factor of devices by packing more good stuff into a smaller space.

But to make a skin-inspired material thats also conductive is a huge challenge. Most of the semiconductor materials that make computing possible are brittle and often crystalline, like diamonds or crystal silicon. The bendier ones like lead or aluminum are definitely not stretchy. A stretchy, bendy semiconducting material is a future-computing unicorn.

Semiconductors are already unicorns within chemistry and circuitry in other ways. A computer chip, which is one of the most common uses of semiconductors, could be built with neither conductors nor insulatorssemiconductors exist in a middle ground that makes it possible to increase and decrease electron flow, powering the infinitesimal logic gates that make up our processors.

Semiconductors can be doped (thats really what its called) to increase their conductivity by turning loose a certain number of electrons. We cant make these modifications to conductive materials, because their electrons are already footloose and fancy free. Insulators are simply too unreactive to be doped.

So within the already special class of semiconductors, a new kind that could be tolerated by and then naturally dissolve within the human body or in nature has almost infinite potential usefulness. Imagine a diagnostic device you could implant and leave for a month without needing to retrieve it in a second operation. Even the mildest, simplest procedures have an amount of risk greater than zero, and the amount gets higher among exactly the population that needs the most diagnostic testing over time.

Are we in for a future where our computers are made of mechanical skin? Try to put the artificial skin phone case out of your mind and instead think of the biological ships that are a mainstay of every science fiction franchise. Star Trek: The Next Generation opens with a living ship held captive in the shape of a space station. By 1995s Star Trek: Voyager, writers already envisioned loose bags of biological material as a power source that would extend the useful life of a ship.

Much of todays cutting-edge space travel research involves self-folding materials that could probably do a lot more if they were also stretchy and elastic. The Stanford team was supported in part by grants from the U.S. Department of Defense, the U.S. Department of Energy, and the U.S. Air Force. In other words, everyone is interested in stretching their resources.

Whether its inside the human body, in space, or thrown into a volcano, versatile semiconductors will likely help us get to the next frontier.

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Stretchy, Degradable Semiconductors Are the Future of Everything - Popular Mechanics