Researchers from the University of California, Davis (UC Davis) have developed a seed-sized radar sensor that can detect movements as small as 1/100^th the width of a strand of human hair.

Capable of detecting movements from objects on a microscopic scale, the device relies on millimeter-wave (mmWave) — an electromagnetic frequency that ranges from 30 gigahertz to 300 gigahertz and is located between microwaves and infrared — radar technology.

Source: UC Davis

Used to power high-speed communication networks such as 5G, mmWave radars send electromagnetic waves to targets to determine their movement, position and speed, according to the waves that are bounced back, the researchers explained.

To filter out the background noise issue commonly associated with mmWave sensors, the researchers modified the sensor's design and structure, thereby eliminating undesired noise from its measurements.

Consequently, the sensor is now capable of detecting alterations in a target's position as tiny as 1/100th the width of a strand of human hair and identifying vibrations as small as 1/1,000th the width of a strand of human hair.

This seed-sized radar sensor, according to its developers, could potentially be used in applications associated with biometric monitoring and security, for instance.

An article detailing the research, "A Highly Accurate and Sensitive mmWave Displacement-Sensing Doppler Radar With a Quadrature-Less Edge-Driven Phase Demodulator," appears in IEEE Journal of Solid-State Circuits.