We utilized surface force spectroscopy (SFS) for direct point-load measurements of the nanomechanical response of the cuticle and pads on the legs and wind-sensing hairs of live wandering. These measurements allowed for calculations of the spring constant of the hair itself, the torsional constants, the elastic modulus of cuticle and pads, and viscoelastic deformation and adhesion of pads (the damping coefficient). In other related study, superficial sensor cupulae of several fish were compared in terms of size, distribution, morphological differences, and mechanical responses (the elastic modulus and the retardation time) in comparison with the micropatterned, dome-shaped hydrogel structures. The applicability of the AFM and SFS for unambiguous and quasi-quantitative measurements of surface nanomechanical properties is discussed and illustrated for a range of model elastic surface layers including composite polymers, [1],[2] grafted block-copolymers[3], homo-[4] and binary brushes[5], in dry state, under liquids, and at elevated temperatures.[1] T. Choi, J.-H. Jang, C. K. Ullal, M. C. Lemieux, V. V. Tsukruk, E. L. Thomas, The elastic properties and plastic behavior of two-dimensional polymer structures fabricated with laser interference lithography, Adv. Funct. Mater. 2006, 16, 1324
[2] V. V. Tsukruk, Z. Huang, Micro-thermomechanical Properties of Heterogeneous Polymer Films,Polymer, 2000, 41, 5541
[3] Y.-H. Lin, J. Teng, H. Shulha, V. V. Tsukruk, In-situ Observation of Switchable Nanoscale Topography for Y-shaped Binary Brushes in Fluids, NanoLett. 2005, 5, 491
[4] M. Lemieux, S. Minko, D. Usov, M. Stamm, V. V. Tsukruk Direct Measurement of Thermo-Elastic Properties Of Glassy And Rubbery Polymer Brushes Grown By Grafting From Approach, Langmuir, 2003, 19, 6126
[5] A. Kovalev, H. Shulha, M. Lemieux, N. Myshkin, V. V. Tsukruk Nanomechanical probing of layered nanoscale polymer films with atomic force microscopy, J. Mater. Res. 2004, 19, 716 |