A team of engineers at Stanford University, Stanford, CA, has invented a wireless pressure sensor that can measure brain pressure in lab mice with brain injuries. But that’s not all. The technology, they say, could one day be used to create skin-like materials that can sense pressure, leading to prostheses with an electronic “sense of touch”.

In one demonstration, the researchers used this wireless pressure sensor to read a team member’s pulse without touching him. In another, this wireless device monitored the pressure inside the skull of a lab mouse, an achievement that could one day lead to better ways to treat human brain injuries.

The wireless sensor is made by placing a thin layer of specially designed rubber between two strips of copper. The copper strips act like radio antennas, while the rubber serves as an insulator.

The technology involves beaming radio waves at this simple antenna-and-rubber sandwich. When the device comes under pressure, the copper antennas squeeze the rubber insulator and move infinitesimally closer together.

That tiny change in proximity alters the electrical characteristics of the device. Radio waves reflected by these antennas slow down in terms of frequency. When pressure is relaxed, the copper antennas move apart and the radio waves accelerate in frequency.

By putting a pyramid-shaped rubber layer between the copper antennas, the engineers were able to exploit the subtle interactions of radio waves and electron clouds to create a pressure gauge.