Dynamic proportional-integral-differential controller for high-speed atomic force microscopy
Dynamic proportional-integral-differential controller for high-speed atomic force microscopy
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DOI：
10.1063/1.2336113
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发表时间：
2006-08-01
影响因子：
1.6
通讯作者：
Ando, Toshio
中科院分区：
文献类型：
--
作者：
Kodera, Noriyuki;Sakashita, Mitsuru;Ando, Toshio
在轻敲模式的原子力显微镜，悬臂尖端间歇地轻敲样品的尖端扫描表面。这种模式适用于成像易碎的样品，如生物大分子，因为悬臂的垂直振荡减少了尖端和样品之间的横向力。然而，轻敲力（垂直力）不一定足够弱的微妙的样品，特别是生物分子系统含有弱分子间或分子内相互作用。轻轻敲需要振幅设定点（即，在扫描期间保持恒定的悬臂振幅）被设置为非常接近其自由振荡振幅。然而，该要求与快速扫描不一致，因为利用这样的设定点，尖端可以容易地从表面完全移除。本文提出了两种装置，以克服这个困难，一个新的反馈控制器（称为“动态比例积分微分控制器”）和补偿器的漂移励磁效率。与其他针对快速扫描而优化的设备一起，这些设备可实现易碎样品的高速成像。(c)2006年，美国物理学会。
In tapping mode atomic force microscopy, the cantilever tip intermittently taps the sample as the tip scans over the surface. This mode is suitable for imaging fragile samples such as biological macromolecules, because vertical oscillation of the cantilever reduces lateral forces between the tip and sample. However, the tapping force (vertical force) is not necessarily weak enough for delicate samples, particularly for biomolecular systems containing weak inter- or intramolecular interactions. Light tapping requires an amplitude set point (i.e., a constant cantilever amplitude to be maintained during scanning) to be set very close to its free oscillation amplitude. However, this requirement does not reconcile with fast scans, because, with such a set point, the tip may easily be removed from the surface completely. This article presents two devices to overcome this difficulty; a new feedback controller (named as "dynamic proportional-integral-differential controller") and a compensator for drift in the cantilever-excitation efficiency. Together with other devices optimized for fast scan, these devices enable high-speed imaging of fragile samples. (c) 2006 American Institute of Physics.