Performance of a microscope with an embedded oscillating pinned-contact liquid lens.

A liquid drop with pinned contact lines in a through-hole behaves as a natural oscillator with low dissipation, while serving as a biconvex lens with a variable focal distance. By embedding such an oscillating liquid lens into a microscope and analyzing it, we show that the object distance of the system can rapidly scan a range of over 1 mm, while maintaining a resolving power comparable to that of the base microscope configuration. Using this scanning object plane enabled by the liquid lens, we show how moving microscopic objects can be observed in three spatial dimensions and time.