Sesame seed-sized radar senses movements a fraction of the width of a hair
Engineers at the University of California, Davis (UC Davis) have developed a new radar sensor that can pick up movements just 100th the width of a human hair. Better yet, the sensor itself is only the size of a sesame seed and is energy efficient.
The system is based on millimeter-wave radar technology, which are short-range radar sensors that, as the name suggests, operate on the millimeter wave frequencies between microwaves and infrared. These sensors can accurately detect incredibly tiny motions from microscopic objects, potentially finding use in security, biometric monitoring and guiding the blind. However, they have issues with power consumption and filtering out background noise.
The UC Davis team’s device is designed to counteract both of those problems. By tweaking the topology of the sensor itself, the team was able to tune it to subtract unwanted noise from its measurements. This allows the sensor to pick up changes in a target’s position that are just 100th of the width of a human hair, and detect vibrations down to 1,000th of a hair.
Unlike other sensors with similar accuracy, this one is far smaller, measuring about the size of a sesame seed. At the same time, its design boosts its energy efficiency and it can be relatively easy to produce.
The researchers say that the sensor is designed to detect how thirsty a plant is by tracking minuscule changes in leaf thickness – a marker of hydration or dehydration. Having a suite of these low-cost sensors could be vital for the agriculture industry. Other potential uses include monitoring the structural integrity of buildings, or for more accurate virtual reality systems, the team says.
The researchers plan to continue refining their design, while allowing other scientists to experiment with it.
The research was published in the IEEE Journal of Solid-State Circuits.
Source: UC Davis