In-Building Metasurface Radar Detects Humans to Reduce HVAC Usage
Duke University was awarded funds by the Defense Advanced Research Projects Agency (DARPA) to develop a unique radar system. It will not only determine occupancy in residential buildings, but do so by means of a unique metasurface or material for the radar antenna that changes shape as part of the detection process. The in-building radars will help save energy consumption for unoccupied rooms in public buildings.
The residential sensor system will employ a dynamic metasurface radar antenna to monitor electromagnetic (EM) waveforms scattered directly and indirectly from a person/target, eliminating the need for direct line of sight between the sensor and the detected person. When a person enters a room, it disrupts the EM scattering patterns already established for that room. The radar system incorporates machine-learning (ML) technology to analyze detected data and determine real-time occupancy within a treated room.
The radar antenna can quickly sample an area, and this information can be used to distinguish humans with the sensitivity to detect even a stationary human’s micro movements such as breathing. Further, the system operates at microwave frequencies, ensuring minimal concern for human safety.
The proposed sensor doesn't require an internet connection or communication links, ensuring minimal security and privacy concerns. If successful, the system promises detection of occupants and near-zero false negative rate without any complex user interactions.
The radar system will operate at microwave frequencies using an antenna based on a scalable soft surface that can continuously reshape itself to mimic different objects. It relies on EM actuation, and, with ML, the surface can adapt to changing environments and broken elements.
The antenna is being developed to detect the shape of targets that haven't been predetermined. While previous efforts at morphing matter have been effective, and triggered by light, they haven't been programmable, such as by means of EM energy. The current research is available in the journal Nature. Research was supported by the National Science Foundation (NSF).