The use of a scanning force microscope with a metallized tip to do selective area oxidation of silicon is demonstrated. Sub-100 nm lines have been achieved. Removal of the oxide lines with buffered hydrofluoric acid reveals trenches in the silicon consistent with silicon consumption in SiO2 formation.

This study investigates the dependence of Ag resistivity on film thickness during temperature ramping as a means to access thermal stability. In situ van der Pauw four-point probe analysis is used to determine the onset temperature; the temperature when the electrical resistivity deviates from linearity during the temperature ramp. At that point, the silver thin films become unstable due to void formation and growth during thermal annealing. The thermal stability of Ag thin films on SiO2 in a vacuum is greatest when thicknesses are greater than 85 nm. Using an Arrhenius relation in terms of onset temperature and film thickness, an activation energy (0.32±0.02 eV) for the onset of agglomeration in Ag thin films on SiO2 ramped at a rate of 0.1 °C/s is determined. This value is consistent with the activation energy for surface diffusion of silver in a vacuum, which is believed to be the dominant mechanism for agglomeration of silver thin film.

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The influence of the mechanical bending, rolling and crimping of flexible screen-printed electrodes upon their electrical properties and electrochemical behavior has been elucidated. Three different flexible plastic substrates, Mylar, polyethylene naphthalate (PEN), and Kapton, have been tested in connection to the printing of graphite ink working electrodes. Our data indicate that flexible printed electrodes can be bent to extremely small radii of curvature and still function well, despite a marginal increase the electrical resistance. Below critical radii of curvature of ~8 mm, full recovery of the electrical resistance occurs upon strain release. The electrochemical response is maintained for submm bending radii and a 180° pinch of the electrode does not lead to device failure. The electrodes appear to be resistant to repeated bending. Such capabilities are demonstrated using model compounds, including ferrocyanide, trinitrotoluene (TNT) and nitronaphthalene (NN). These printed electrodes hold great promise for widespread applications requiring flexible, yet robust non-planar sensing devices.