Research
| Use of nanomechanical resonators has recently found wide applications in biosensors. With their superior sensitivity and potential for multiplexing they emerge as an alternative to existing detection techniques of pathogens. Within our research agenda on bioMEMS, a biosensor is developed as a joint effort within the College of Engineering. The sensor is based on dynamic-mode operation of nanomechanical cantilever arrays with electromagnetic actuation. Ni cantilevers are fabricated with diffraction gratings at their tips. Diffraction gratings serve as a moving surface, whereas the stationary Si substrate, on which devices are fabricated, is a measurement reference. Intensity modulation in a diffraction order can then be monitored with a photodiode and cantilever's vibration frequency can thus be measured. Simple architecture with the possibility of extension to a vast array combined with liquid operation and immunity against environmental noise provide promising aspects for a low-cost, label-free biosensor with parallel readout. Furthermore, the lack of any electrical connection to the sensor raises the possibility of a portable device with a disposable cartridge. Transducer calibration is carried out with commercial laser Doppler vibrometers. Biological demonstrations include so far opioid receptors and Hepatitis virus markers. |
 Figure 1.
Biosensor systems based on nanomechanical resonators. Click image to enlarge |