Department of Mechanical Engineering, Boston University, Boston, MA, 02215, USA.
Department of Chemistry and Biochemistry, University of Maryland, College Park, MD, 20742, USA.
Nat Commun. 2021 Jan 15;12(1):393. doi: 10.1038/s41467-020-20612-3.
Resolution and field-of-view often represent a fundamental tradeoff in microscopy. Atomic force microscopy (AFM), in which a cantilevered probe deflects under the influence of local forces as it scans across a substrate, is a key example of this tradeoff with high resolution imaging being largely limited to small areas. Despite the tremendous impact of AFM in fields including materials science, biology, and surface science, the limitation in imaging area has remained a key barrier to studying samples with intricate hierarchical structure. Here, we show that massively parallel AFM with >1000 probes is possible through the combination of a cantilever-free probe architecture and a scalable optical method for detecting probe-sample contact. Specifically, optically reflective conical probes on a comparatively compliant film are found to comprise a distributed optical lever that translates probe motion into an optical signal that provides sub-10 nm vertical precision. The scalability of this approach makes it well suited for imaging applications that require high resolution over large areas.
分辨率和视场通常是显微镜中的一个基本权衡。原子力显微镜（AFM）是一种关键的例子，在这种显微镜中，悬臂探针在扫描基底时会受到局部力的影响而发生偏转，高分辨率成像主要限于小区域。尽管 AFM 在材料科学、生物学和表面科学等领域产生了巨大的影响，但成像区域的限制仍然是研究具有复杂层次结构的样品的一个关键障碍。在这里，我们通过结合无悬臂探针结构和可扩展的光学探测探针-样品接触的方法，展示了具有>1000 个探针的大规模并行 AFM 是可能的。具体来说，在相对柔软的薄膜上的光学反射锥形探针被发现包含一个分布式光杠杆，它将探针的运动转化为光学信号，从而提供小于 10nm 的垂直精度。这种方法的可扩展性使其非常适合需要在大面积上实现高分辨率的成像应用。
