Dr. Universe: What is a microchip, how do they work, and what are they used for? —Brook, Doncaster, England
Microchips are smaller than your fingernail and packed with itty-bitty electronic parts. These parts are hundreds of times thinner than the hairs on your head, but sometimes you’ve got to think small to think big.
More than 50 years ago, humans invented vacuum tubes that made electricity flow in different directions or get stronger. The tubes made it possible to invent televisions and computers, even if they were the size of dinosaurs. OK, they weren’t that big, but computers really could fill a whole room. The tubes tended to get really hot and burn out.
Then, the transistor was invented. Transistors also help electricity flow, stop, and go. Transistors are hundreds of times smaller than bulbs, so you can use them to make circuits that are connected to one another, or integrated. If a circuit is a kind of road where electric signals flow, transistors are a kind of traffic light, or switch.
When you put a bunch of these electrical parts on a chip, they can pass on all kinds of information. Microchips are in practically every electronic gadget we use today. I once went to the vet and came home with a microchip of my own, under my skin.
The microchip doesn’t do much by itself. It needs a power source to work. Information in microchips is stored in a kind of alphabet called binary code. Those transistors are important because they control which letters are being used and tell the chip how to work. For example, people at shelters can scan a chip for an animal’s special ID number and help chip-carrying pets find their owners.
Microchips are useful in other ways, too. Biologists can use them to track wild animals and learn about migration. Lots of chips are being added to credit cards for more secure payments. Thirsty plants can even use chips to let people know when they need water.
My friend Prashanta Dutta is an engineer who designs and studies microchips in a lab here at Washington State University. He and his team are learning how microchips can improve people’s heath. They use chips to see what is going on in people’s blood and learn more about how the body works.
“One chip will be able to simulate a human brain to study brain function,” he said. “It will help us develop drugs for brain cancer and brain-related diseases people sometimes face when aging.”
In the lab, they design circuits on a flexible material. It lets them test out the chip on a bigger scale, before they shrink it down. Most chips are made from silicon, which is a main ingredient in sand and glass. Machines can create a base for the microchips by slicing wafers off a kind of “silicon salami.” Mm ... salami. But some scientists recently discovered how to make a chip using wood. There’s lots of room to explore when it comes to materials and how little devices can help solve some of our greatest challenges.