Cantilever developments for combinatorial force microscopy

J.C. Mabry, T. Yau, H. W. Yap, J.-B.D. Green

Department of Chemistry and Biochemistry, Southern Illinois University, Carbondale, Illinois 62901, USA.

Force microscopy has demonstrated the capability to determine structural, mechanical, chemical, and biochemical properties of interfaces with nanometer resolution. We are developing a technique that uses an inverted AFM arrangement, where the cantilever has no tip and the substrate is an array of tips. In this design, the cantilever acts as a sample to be imaged by any of the tips in the tip array. For some initial experiments, the tip array has been patterned with a small library of molecules, creating an array of chemically distinct tips. Subsequently, these tips were used to image a wide range of materials, which were immobilized on the cantilever. This allows many chemically distinct tips to image the same material under nearly identical conditions and in a rapid manner. In additional studies, the cantilever has also been patterned with a small library of molecules to demonstrate some capabilities for combinatorial analysis. Some advantages, limitations, and future directions of this technique will be briefly discussed.