A bullet and a knife blade hidden insdie a toy; a terahertz image taken with a new silicon chip reveals the nasty secret hidden within.Kaushik Sengupta/Caltech
An ostensibly innocent child's toy is cut open to reveal a hidden bullet and blade, detected by the new terahertz imaging chip.Kaushik Sengupta/Caltech
Caltech electrical engineers Kaushik Sengupta and Ali Hajimiri demonstrate their new terahertz imaging chip.Caltech
The new terahertz chips, developed by Caltech electrical engineers, shown with a penny for scale.Kaushik Sengupta/Caltech
A new low-cost, imager chip could give your average smartphone the ability to see through walls and objects Superman style.
The chip would not only allow you to see through a wall, but to see what is hidden inside an object and create images of what is inside. Suspicious package left on a bus? You could pull out your smartphone, scan it over the package and reveal whether it is hiding a bomb.
The scanner can detect guns, explosives and razor blades hidden within a range of materials. It can even determine the fat content of chicken tissue -- making you wonder if you could use your smartphone to scan your date, and not just your meal.
This month’s IEEE Journal of Solid-State Circuits details California Institute of Technology electrical engineers Ali Hajimiri and Kaushik Sengupta, who have developed this tiny technology.
The tech uses chips that radiate high-frequency electromagnetic terahertz waves, from 0.3 to 3 THz -- between microwaves and far-infrared radiation on the electromagnetic spectrum.
Terahertz waves can penetrate a whole range of objects and packaging materials and produce high-resolution images of what they find. They can also detect biological weapons, illegal and pharmaceutical drugs or explosives.
It achieves this detection without the ionizing damage that comes with X-rays.
Part of the breakthrough is miniaturizing a terahertz imager cheaply. Current systems are both expensive and giant –unlikely to fit in your smartphone.
Silicon chips are not designed to operate at terahertz frequencies, and the team had to harnesa the collective strength of many transistors operating in unison to boost the strength of the signal.
Their approach means operating at very high frequencies without a large power source, with large elements producing the power. At such frequencies, traditional tiny wire antennas wouldn’t work, so another challenge was figuring out how to transmit the terahertz signal.
Their solution: make the whole silicon chip into an antenna by integrating small metal segments that can work together simultaneously to achieve the right signal strength.
The terahertz signals that can be dynamically programmed to point in a specified direction.
The publication asserts their new chips make signals a thousand times stronger than current approaches, 300 times faster than today’s cell phone chips and that they achieved operating transistors at approximately forty to fifty percent above the cut-off frequencies.
Beyond security applications and putting the ability to scan for hidden dangers with your smartphone, the chip has potential for wireless communications, health care, and touchless gaming.
CalTech hopes the technology will enable a new generation of sensors and may even lead to noninvasive cancer diagnosis.
Ballet dancer turned defense specialist Allison Barrie has traveled around the world covering the military, terrorism, weapons advancements and life on the front line. You can reach her at mailto:firstname.lastname@example.org or follow her on Twitter @Allison_Barrie.