“CMOS is affordable and can be used to make lots of chips," Dr. O explained. “The combination of CMOS and terahertz means you could put this chip and receiver on the back of a cellphone, turning it into a device carried in your pocket that can see through objects."

In developing their chip, the researchers, who are concerned about privacy, are focusing on a range of less than four inches. Once the chip hits the mainstream, though, there are plenty of folks, many of them wearing uniforms, who have fewer qualms than the researchers about boosting the range of the chip.

Aside from its snooping potential, the chip could have a number of beneficial uses. For example, it could be used in a high-tech wall stud finder and to authenticate documents. Businesses could use it to detect counterfeit money and manufacturers could use it to improve the quality of their products.

The chip could have intriguing potential in the medical field, too. It could be used to detect cancer tumors, diagnosing disease through breath analysis, and monitoring air toxicity.