Wireless Sensors and Actuators Based on Magnetostrictive Resonators

Biosensors based on magnetostrictive resonators, magnetostrictive cantilever and magnetostrictive particles (MSPs), have been developed in recent years [1]. Due to their magnetic nature, these biosensors are wireless, which makes them to a great candidate for in-situ detection. Both phage and antibody, which are immobilized onto the surface of the magnetostrictive resonator, have been used as biological molecular recognition elements. The performance characterization of these biosensors shows that these biosensors work well in liquid and exhibit a high sensitivity for the detection of bacteria in water [2].

It is well known that the sensitivity of MSP increases with reducing size of the MSP. Therefore, a much better sensitivity is expected for the MSPs with a smaller size. The above results demonstrate that the biosensors based on the magnetostrictive resonators are suitable for in-situ detection of pathogens in liquid media. To fully develop the detection technology based on magnetostrictive resonators for in-field detection, a small size interrogation unit/device is required. A new methodology was developed recently [3]. Based on this technology, a handheld device is developed to characterize the response of the biosensors based on magnetostrictive resonators.

For the detection of pathogenic species in food samples, sampling is always a key issue, since the locations of the target species are unknown and the biosensors have to be brought into reaction with the target species. It is experimentally found that an MSP biosensor can act as an actuator when it is driven under a frequency different than the resonant frequency.  In the experiments, it is found that the moving speed of the MSP actuator is dependent on the frequency. A freestanding MSP is an actuator that can move along its length direction without the limitation in displacement and the motion can be both directions.

REFERENCES

[1] K. W. Zhang, L. Zhang, L. L. Fu, S. Q. Li, H. Q. Chen, and Z.-Y. Cheng, Magnetostrictive resonators as sensors and actuators, Sensors & Actuators: A. Physical, 200, 2-10 (2013).

[2] K. W. Zhang, L. L. Fu, L. Zhang, Z.-Y. Cheng, and T.-S. Huang, Magnetostrictive particle based biosensors for in-situ and real-time detection of pathogens in water, Biotechnology and Bioengineering, 111, 2229 (2014).

[3] Z.Y. Cheng, A.X. Zhang, K.W. Zhang, B.A. Chin, Systems for Characterizing Resonance Behavior of Magnetostrictive Resonator(s), U.S. Patent Application
No. 20120280682 (2012).