Ignat Ioan, Schuster Bernhard, Hafner Jonas, Kwon MinHee, Platz Daniel, Schmid Ulrich
Institute of Sensor and Actuator Systems, TU Wien, Gußhaustraße 27-29, 1040 Vienna, Austria.
Beilstein J Nanotechnol. 2023 Jan 19;14:123-132. doi: 10.3762/bjnano.14.13. eCollection 2023.
Atomic force microscopy (AFM) is highly regarded as a lens peering into the next discoveries of nanotechnology. Fundamental research in atomic interactions, molecular reactions, and biological cell behaviour are key focal points, demanding a continuous increase in resolution and sensitivity. While renowned fields such as optomechanics have marched towards outstanding signal-to-noise ratios, these improvements have yet to find a practical way to AFM. As a solution, we investigate here a mechanism in which individual mechanical eigenmodes of a microcantilever couple to one another, mimicking optomechanical techniques to reduce thermal noise. We have a look at the most commonly used modes in AFM, starting with the first two flexural modes of cantilevers and asses the impact of an amplified coupling between them. In the following, we expand our investigation to the sea of eigenmodes available in the same structure and find a maximum coupling of 9.38 × 10 Hz/nm between two torsional modes. Through such findings we aim to expand the field of multifrequency AFM with innumerable possibilities leading to improved signal-to-noise ratios, all accessible with no additional hardware.
原子力显微镜（AFM）被高度视为窥探纳米技术下一个发现的透镜。原子相互作用、分子反应和生物细胞行为的基础研究是关键重点，要求分辨率和灵敏度不断提高。虽然诸如光机械学等知名领域已朝着出色的信噪比迈进，但这些改进尚未找到应用于AFM的切实可行方法。作为一种解决方案，我们在此研究一种机制，即微悬臂梁的各个机械本征模相互耦合，模仿光机械技术以降低热噪声。我们研究AFM中最常用的模式，从悬臂梁的前两个弯曲模式开始，并评估它们之间放大耦合的影响。接下来，我们将研究扩展到同一结构中可用的本征模领域，并发现两个扭转模式之间的最大耦合为9.38×10 Hz/nm。通过这些发现，我们旨在扩展多频AFM领域，带来无数可能性，从而提高信噪比，且无需额外硬件即可实现。
