We developed a novel cantilever-based optical interfacial force microscope (COIFM) to study molecular interaction in liquid environments. The force sensor was created by attaching a chemically etched optical-fiber tip to the force sensor with UV epoxy, and characterized by imaging on a calibration grid. The performance of the COIFM was then demonstrated by measuring the force between two oxidized silicon surfaces in 1 mM KCl as a function of distance. The result was consistent with previously reported electrical double layer forces, suggesting that a COIFM using an optical-fiber tip is capable of measuring force in a liquid environment.
Kim, Byung I.; Smith, Luke; Tran, Thanh; Rossland, Steven; and Parkinson, Erik. (2013). "Cantilever-Based Optical Interfacial Force Microscope in Liquid Using an Optical-Fiber Tip". AIP Advances, 3(3), .