A battery-free, wireless device that can detect coronavirus particles in air has been designed by researchers in Japan.
The device is engineered with a magnetostrictive clad plate composed of iron, cobalt and nickel, generating power via alternative magnetization caused by vibration. The vibration resonance frequency of the plates, which are coated with the receptor protein coronaviruses use to enter human cells, changes when the virus is absorbed, indicating the presence of COVID-19 agents in the air.
The sensor was constructed with a modified 0.2 mm thick Fe-Co/Ni plate with a rectifier/storage circuit that harvests bending vibration energy and enables the wireless transmission of information. The plate was demonstrated to transmit signals with the power obtained from bending vibration at 115 Hz or 116 Hz. A change in clad plate weight affected the resonance frequency and altered the transmission intervals, suggesting it could detect any substances that adhered to the clad plate.
The clad plate was then immersed in a CD13 protein solution to form a biorecognition layer specific to human coronavirus 229E (HCoV-229E). When the coated clad plate was subjected to bending vibration during sensing experiments, the resonance frequency decreased after HCoV-229 was absorbed, verifying whether the charged power could transmit virus detection as a signal.
With modifications to the biorecognition layer, the device developed by researchers from Tohoku University, University of Yamanashi and Tohoku Steel Co. and described in Sensors and Actuators A: Physical could be applied to the detection of other pathogens.