This Vibrating Metal Plate Sends Out a Wireless Warning of Coronavirus Exposure — Without Batteries

Researchers from Japan's Tohoku University, the University of Yamanashi, and Tohoku Steel have developed an energy-harvesting sensor device capable of detecting coronavirus particles and droplets and communicating a warning — working entirely without batteries.

"We know that resonance frequency changes when the weight of a magnetostrictive material changes," explains co-author Fumio Narita of the team's inspiration for the project, "but we set out to answer whether this is also the case when a virus is absorbed and if this absorption is detectable."

The idea: To create a sensor from a magnetostrictive clad plate made from iron, cobolt, and nickel and which generates power through alternative magnetization when vibrated. As the plate interacts with its surroundings, it resonance frequency alters — and it's this altered frequency that can be used to detect when the sensor has come into contact with the coronavirus.

Normally, however, the plate alters its resonant frequency according to its weight — meaning it can detect when something has adhered to its surface, but without knowing exactly what. To tune the sensor for virus detection, the team coated it with a protein solution, which could absorb the coronavirus — allowing it to trigger only when the virus was present.

"We were able to confirm that the magnetostrictive composite material can detect the virus and transmit this detection data using power generated by itself," Narita explains. "The self-sustaining nature of the device renders it possible to link it to IoT [Internet of Things] technologies in the future, something not capable with current biosensors."

The researchers' work is available under open-access terms in the journal Sensors and Actuators A: Physical; Narita says the team is hoping to extend the device to detect additional pathogens in the future including MERS, SARS, and SARS-CoV-2, the virus responsible for COVID-19.