NanoSonix SNFUH setup is actually piggybacked on a conventional atomic force microscope (AFM). The high quality and far-reaching applications of this imaging technique is at present constrained by the optical feedback modality in commercial AFM’s platform which restricts our measurement bandwidth up to ~ 600kHz and thus, the achievable depth resolution.

Our innovative microcantilever with electronic position readout has solved this problem dramatically, allowing us to generate high resolution SNFUH image with increased the speed and throughput,. This is accomplished by means of embedding geometrically configured stress-sensing MOSFET (metal-oxide field effect transistor) in a high stress region of the microcantilever to measure cantilever bending. Deflection in cantilever is measured as a change in MOSFET drain current (ID). When the cantilever bends, stress is applied to the channel region of the embedded MOSFET to modulate its carrier mobility, which leads to measurable and reproducible change in drain current.

NanoSonix novel MOSFET-embedded microcantilevers exhibit measurable, consistent and reproducible change in the drain current even for deflection down to < 5 nm with a current sensitivity between 0.1-0.2 mA per nanometer deflection, over a very large bandwidth (up to 100MHz, >100 times higher than optical AFM).. Such high deflection sensitivity is achievable by driving the MOSFET at a suitable gate voltage (VG). Thus, the MOSFET not only works as a stress sensing device but also acts as an amplifier (similar to optical amplification), enabling detection of cantilever bending at high sensitivity. Further, the 1/fnoise of the MOSFET readout is significantly lower than that of the piezoresistive techniques used as alternatives to optical detection.

NanoSonix MOSFET embedded cantilever based all-electronic SNFUH system (which is under development) will facilitate direct and quantitative imaging of the elastic (static) and viscoelastic (dynamic) response of a variety of nanoscale materials and device structures with high spatial and lateral resolution (offered by wide frequency bandwidth of MOSFET readout) with potential for 3-D tomography. As these capabilities will operate in a manner analogus to commercially available scanning probe microscopes (SPMs), it will catapult many other SPM-based techniques to new heights. Sensing and actuation is another area where MOSFET embedded cantilevers promise to have great future.