Have you watched Inner Space, an 80s sci-fi comedy about a microscopic manned capsule injected into a human? Despite the fact that we are still far from creating submarines floating in the human body, technological advances allow us to create computers so tiny that their introduction into living tissues no longer seems to be a figment of the imagination of science fiction writers.
Indeed, it has been 20 years since the English scientist Kevin Warwick first implanted a silicon RFID transmitter in his arm to remotely control computers in doors, lights and other devices. He then took it one step further, linking the device to his own nervous system to control a robotic arm, and earned the nickname "Captain Cyborg."
Although stories of this kind do not appear every day, the pace of development of microcomputer technology has not slowed at all. The ingenuity of some of the new developments is surprising.
The smallest computers
For example, earlier this year, a team at the University of Michigan led by professor of electrical and computer engineering David Blaau used an energy-efficient processor created by Arm to create the world's smallest computer.
A device with a facet of just 0.3 millimeters is ten times smaller than the previous record holder, a solar-powered computer the size of a grain of salt. Because temperature and pressure sensors can be embedded in the new device, Blaau's team suggests that, among other things, a computer can be implanted in tumors to determine if they shrink after chemotherapy or not. (Research shows tumors can have a higher temperature than healthy tissue.)
While the development of tiny computers is impressive, there are obstacles preventing their widespread adoption in the healthcare and other sectors. One of the biggest challenges is assembling batteries small enough to power devices. As the size of the batteries shrinks, so does the amount of energy they store. The batteries needed for tiny computers are significantly smaller than the typical small batteries used to power other devices like pacemakers and cochlear implants, and Blaau said they could have a capacity a thousand times less.
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One possible solution is to find ways to frequently recharge devices. For example, beams of infrared light can remotely charge sensors implanted in laboratory mice. Scientists are also investigating how to create electricity for tiny computers using a technique known as thermoelectric energy harvesting, but have yet to be successful on such a small scale. For this latter method to work, there must be a temperature difference between the two surfaces of the device, but the new tiny computers are so small that it is difficult to make one part much warmer than the other. Other methods that are still being researched include using glucose molecules as an energy source.
An effective solution would be to simply save a small amount of power that can be stored in a tiny battery. Blaau and his team have found that they can drastically reduce energy consumption by only waking computers occasionally to perform calculations, and then putting them back to sleep.
In addition to maximizing the amount of time that tiny computers sleep, engineers can reduce power consumption by cutting down on the amount of electricity that computers consume while awake. Blaau and his team were able to reduce the power consumption of their computer to an infinitesimal 30 picowatts - 300 trillionths of a watt - by modifying the transistors used, downsizing some of the chips, and optimizing some of them.
If engineers can overcome technological hurdles, tiny computers could promise us a revolution. For example, CubeWorks, a Michigan Micro Mote (M3) company, has developed a networked microsensor system that can be embedded in objects we use every day, such as smart home systems, wind farms and glucose monitoring devices, and then connect to the "Internet of Things". Powered by the sun, these computers are able to collect information about ambient temperature and pressure, as well as acquire digital images and track movement within a specific area. Systems like these may one day transform our interactions with everything from the buildings we live in to the clothes we wear.
Yes, we cannot yet launch submarines in our bodies, but millimeter computers will hit the market in the next decade. And they threaten to change our world beyond recognition.
Ilya Khel