Your body and your smartphone — or any other electronic device — don’t speak the same language. One uses electrons, the other protons to send information. But scientists at the University of Washington are working on ways to help the two understand each other through a new type of transistor. And this week they’ve announced a breakthrough transistor that uses materials derived from — wait for it — crab shells and squid parts.
UW researchers say this new type of transistor could one day understand or even control body functions. Materials scientists are looking at these proton-based microscopic transistors for future advances in prosthetics and biological sensing. The study of the itsy-bitsy transistor built by the UW researchers appeared this week in Nature Communications.
Here’s how it could work, according to UW:
In the body, protons activate “on” and “off” switches and are key players in biological energy transfer. Ions open and close channels in the cell membrane to pump things in and out of the cell. Animals, including humans, use ions to flex their muscles and transmit brain signals. A machine that was compatible with a living system in this way could, in the short term, monitor such processes. Someday it could generate proton currents to control certain functions directly.
A first step toward this type of control is a transistor that can send pulses of proton current. The prototype device is a field-effect transistor, a basic type of transistor that includes a gate, a drain and a source terminal for the current. The UW prototype is the first such device to use protons.
Because their device’s proton current can be switched on and off, it can act as its own kind of electronic current, according to Marco Rolandi, a UW assistant professor of materials science and engineering. The transistor itself is “a twentieth the width of a human hair,” or about 5 microns wide. It is made of a compound, chitosan, found in both crab shells and squid pen (the structure inside a squid’s body that muscles attach to).
The reason they like chitosan so much for this transistor is because it’s “compatible with living things” and it “works remarkably well at moving protons.”
This type of chitosan absorbs water and forms lots of hydrogen bonds. Protons then move along quickly, from one hydrogen bond to the next, according to the study. So will these scientists go hunting for dead crabs or harvesting squid for chitosan? No. They want to take it from the leftovers at restaurants. Sounds kind of gross, but environmentally conscious.
It looks like it’ll be a while before machines will be controlling our bodies. The first applications of this research will come some time “in the next decade or so,” and will be aimed at direct sensing of cells in a lab, researchers say. But further out they could be implanted directly in living organisms to monitor or control bodily processes.
Image via University of Washington