Figure 1.

Experimental Setup. (A) Common TEM substrates are 3 mm circular copper grids or 3 mm silicon chips. Larger substrate formats are not commonly accepted by commercial TEM holders, since most are designed for 3 mm diameters. (B) A 5.4 mm square chip allows for more robust use in microfluidic devices compared to a smaller 3 mm chip or grid, which is more difficult to handle. (C) Image of an unmodified FEI TECNAI G20 TEM holder containing a 3-mm silicon chip, held in place by a cantilever with circular aperture (sample affixation clip), with a 5.4 × 5.4-mm² NPN chip on the end for scale. (D) Image of a modified FEI TECNAI G20 TEM holder containing 5.4 × 5.4 mm² NPN chip, with the affixation clip raised. The viewing area remains limited to the 2.8 mm circular aperture of the clip. (E) Tilted views of the sample are available using this modified holder, which are necessary for electron tomography.