A Georgia Tech inventor has developed a AFM cantilever structure with integrated electrostatic (or piezoelectric) actuators, which employ electrostatic electrode pairs that are micromachined together with the AFM cantilever using thin film deposition and patterning techniques such as photolithography. Extra capacitive detection electrodes can be also integrated for enhanced sensitivity. Furthermore, optical interferometric detection, which yields information of direct tip displacement, can be added as a feature to the integrated electrostatic actuators by fabricating actuation electrodes and a reflective diffraction grating on transparent AFM cantilevers. This novel cantilever structure simplifies the operation of AFM. It provides accurate force measurements with nanoscale lateral resolution and enables operation in both air and liquid environment. Such an integrated structure is especially suitable for AFM array operation, where each cantilever can be individually actuated in DC-MHz frequency range. In addition, all of these AFM cantilevers can also be used with conventional optical beam-bounce technique available in commercial AFM systems. The technology could be used for scanning probe microscopy, force spectroscopy of molecules, or nanoindentation measurements of mechanical properties.
- Efficient — enables fast actuation with integrated electrostatic actuators
- Accuracy — accurate force measurements with nanoscale lateral resolution
- Improved speed — improvement for both speed of actuation and accuracy of detection
- Multiple applications — could be used both in gas and liquid media
- High-throughput — arranged in an array for high-throughput drug discovery and proteomics
- Drug discovery
- High speed 1-D/ 2-D array for probe lithography
Atomic force microscopy (AFM) has become a powerful tool to study surface properties. However, the performance of conventional AFM is still limited by its slow speed of imaging due to the requirement of an external z-axis actuator. Thus, it is desired that an integrated sensing mechanism can be incorporated with the AFM cantilever so that higher scanning rate and sensitivity can be achieved.