Adhesion force studies using a dangling optical lever with variable sensitivity.
Adhesion force sensed using tips on microcantilevers via an optical lever requires care to ensure that the tip alone contacts the liquid; is sensitive to high degrees of measurement error from departure from the laser spot; requires specialized optics and careful arrangement to produce a small laser probing spot; and limits the distance between cantilever and photodiode for increased force sensitivity. An alternative scheme, using microimaging electronic speckle pattern interferometry to monitor the deformation of a tipless microcantilever, necessitates that the beam be rigid enough to be independent of the drop location; is not amenable to very low adhesion force measurement; and requires more complicated instrumentation. All these limitations can be effectively circumvented by a variable sensitivity scheme described here that harnesses the geometric properties of a dangling cantilever operating as an optical lever.
Laboratory for Optics, Acoustics & Mechanics, Department of Mechanical & Aerospace Engineering, Monash University, Clayton, VIC 3800, Australia.
Yohannes
Y
Panduputra
Tuck Wah
TW
Ng
Adrian
A
Neild
William Yeong Liang
WY
Ling