Designing Array-Atomic Force Microscope for Real-Time Nanoscale Multi-Parametric Structure-Function Study
- Author(s): Yang, Qingqing
- Advisor(s): Lal, Ratnesh
- Liu, Zhaowei
- et al.
Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multi-point study is challenging owing to the intrinsic limitations of existing technological approaches.
In this dissertation, a prototype dispersive optics-based array AFM platform capable of simultaneously monitoring multiple probe-sample interactions was described. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, in order to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This new design provides a remarkably simplified yet effective solution to overcome the optical crosstalk, while maintaining sub-nm sensitivity and compatibility with probe-based sensors. The versatility and robustness of our system was demonstrated on parallel multi-parametric imaging at multi-scale levels: ranging from surface morphology to hydrophobicity mapping in both air and liquid; mechanical wave propagation in polymeric films and the dynamics of living cells. Meanwhile, I also explored batch microfabrication of independent conductive AFM cantilever array compatible with the SEA-AFM system to further expand the platform’s application of studying the intercellular mechanical/electrical signal propagation.
This multi-parametric, multi-scale approach provides new opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks.