Noncontact scanning impedance imaging has been presented as a method to provide high resolution, high contrast images for a variety of material systems. This technique combines electrical impedance measurements with very high resolution scanning. This article reports on efforts to scale this technique down to the very important single micron range and reveals measurements for both thick and thin samples with a measured minimum resolution below 30 µm. A design for a shielded impedance probe applicable to this process is outlined and probes of several different sizes were made and tested. Fabrication of these impedance probes is explained and a testing methodology to characterize the probes' imaging capability is outlined. Measured results are reported and compared to a predictive model based on image blurring. Two-dimensional impedance images of objects have also been made indicating good image contrast and high resolution. Based on measured data and the model, scaling down to submicron resolution dimensions should be possible given small diameter probes and thin test samples.
(c) 2004 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. The following article appeared in The Journal of Chemical Physics and may be found at http://link.aip.org/link/?RSINAK/75/4610/1 ;