Engineers at the University of California, Davis (UCDavis) have developed a new radar sensor that can capture motion 100 times the width of a human hair. Even better, the sensor itself is 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 millimeter-wave frequencies between microwaves and infrared. These sensors can accurately detect extremely small movements of microscopic objects and have potential applications in areas such as security, biometric monitoring and guidance for the blind. However, they have issues with power consumption and filtering background noise.
The UC Davis team's device aims to solve both of these problems. By adjusting the topology of the sensor itself, the team was able to tune it to subtract unwanted noise from the measurements. This enables the sensor to detect changes in target position as small as one percent of the width of a human hair, and to detect vibrations as small as one thousandth the width of a human hair.
Unlike other sensors with similar accuracy, this one is much smaller, measuring about the size of a sesame seed. At the same time, its design improves energy efficiency and is relatively easy to produce.
The researchers say the sensor is designed to detect drought levels in plants by tracking small changes in leaf thickness, a sign of hydration or dehydration. Having a suite of these low-cost sensors is critical for agriculture. The team said other potential uses include monitoring the structural integrity of buildings, or more accurately, virtual reality systems.
The researchers plan to continue refining their design while allowing other scientists to conduct experiments.
The research was published in the IEEE Solid-State Circuits Magazine.