Brace yourselves, sci-fi fans: scientists have (apparently) invented the “tricorder,” the somewhat magical device from Star Trek used to diagnose a range of medical disorders in an instant. Although this isn’t quite what’s been constructed, the so-called tricorder itself is quite remarkable. As new research published in the journal Applied Physical Letters reveals, this device uses microwaves and ultrasound to detect hidden objects, ranging from buried explosives to maybe even cancerous tumors.
A group of Stanford electrical engineers, led by assistant professor Amin Arbabian and research professor Pierre Khuri-Yakub, produced this new device, which grew out of a challenge by the scientific and technological wing of the U.S. military, DARPA. The agency wanted new techniques designed to locate buried improvised explosive devices (IEDs) that are invisible to metal detectors. Of course, the detectors have to function without touching an object, because of the risk of explosion.
This new device generates focused microwaves, which caused the molecules within various materials to vibrate, and heat up – just by a mere thousandth of a degree, without causing damage. In addition, the vibration frequency of one material would be different to another. For example, plastic vibrates and heats up less rapidly when exposed to microwave radiation than wet muddy soil would. The same principle applies to different types of metals, which could be identified based on their specific frequencies.
It is this vibration effect that generates ultrasonic waves that are emitted out into the environment. These sound waves – beyond the hearing range of humans – can be detected by a receiving instrument. The speed and time in which the soundwaves take to reach the detector give a measure of distance, which can ultimately be used to generate a virtual image of the hidden object.
When ultrasound is emitted through the air after traveling through an object, it slows down and becomes far more difficult to detect. A series of ultrasensitive ultrasonic detectors on the “tricorder” device mean that this loss is compensated for, therefore it can effectively detect hidden explosive devices from a safe distance.
“What makes the tricorder the Holy Grail of detection devices is that the instrument never touches the subject,” Arbabian said in a statement.
That’s not all: the reason this device has been nicknamed the tricorder by the researchers is that also has medical applications. The same team implanted a plastic polymer “target” – a stand-in for a tumor – within a block of gel made from seaweed, which could represent human tissue. Holding the device around 30 centimeters (1 foot) away from the materials, the device could precisely pinpoint the location of the concealed target. Identifying malignant tumors within human organs using this tricorder, then, is now theoretically possible.
“We've been working on this for a little over two years,” Khuri-Yakub said in the statement. “We're still at an early stage but we're confident that in five to 10 to 15 years, this will become practical and widely available.”
