X-ray vision chip gives phones 'Superman' power to view objects through walls

Scientists have developed an imaging chip that could equip future smartphones with "Superman-inspired" X-ray vision — albeit operating within a much more limited range than the caped Kryptonian superhero.

The experimental chip consists of an array of three sensor pixels that emit and receive high-frequency radio signals in the millimeter-wave (mmWave) band of the electromagnetic spectrum. Signals reflected back from the target object are then amplified and mixed by onboard components, enabling outlines of the object to be viewed on a display.

In tests, the chip could detect an object behind cardboard at a distance of around 0.39 inches (1 centimeter). The researchers published their findings Jan. 5 in the journal IEEE Transactions on Terahertz Science and Technology.

It took 15 years of work — and an improvement in pixel performance by 100 million times — to make the chip small enough to fit in a mobile device, the researchers said in a statement. In the future, smartphones equipped with the chip may be capable of detecting the contents of envelopes or packages, or could be used to find studs, wires or cracked pipes behind walls.

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"We designed the chip without lenses or optics so that it could fit into a mobile device. The pixels, which create images by detecting signals reflected from a target object, have the shape of a 0.5-mm square, about the size of a grain of sand," said co-author of the paper Wooyeol Choi, assistant professor of electrical engineering at Seoul National University, in the statement.

Beyond making it possible to peer through walls and inside envelopes, the new imaging tech may find applications in medicine and healthcare, the researchers said. They likened the technology to that already used in passenger scanners found at airports — though they noted that their imager chip does not use microwaves.