New imaging chip could allow hand-held devices to see through walls A bullet and a knife blade hidden inside a toy. The teraherz image reveals the hidden objects without needing to cut open the toy. Credit: Kaushik Sengupta/Caltech PASADENA, Calif., Dec. 11 (UPI) -- Smartphones may soon have the capability of seeing through walls courtesy of a tiny, low-cost imaging chip, U.S. researchers say. Two electrical engineers at the California Institute of Technology have invented tiny inexpensive silicon microchips that generate and radiate high-frequency electromagnetic waves, called terahertz waves. These waves are in a largely unused region of the electromagnetic spectrum between microwaves and far-infrared radiation and can penetrate a host of materials without the ionizing damage of X-rays, a Caltech release said Monday. When built into hand-held devices, they could lead to a range of applications in fields ranging from homeland security to wireless communications to healthcare, the researchers said. "Using the same low-cost, integrated-circuit technology that's used to make the microchips found in our cell phones and notepads today, we have made a silicon chip that can operate at nearly 300 times their speed," electrical engineering Professor Ali Hajimiri said. These chips will enable a new generation of extremely versatile sensors. Waves in the terahertz frequency range can easily penetrate packaging materials and yield high-resolution images of hidden objects, and can also detect the chemical fingerprints of pharmaceutical drugs, biological weapons, or illegal drugs or explosives, Hajimiri and postdoctoral scholar Kaushik Sengupta said.