Microcolumn imaging

Experimental work reported below shows that such tests can be used to predict microencapsulated system behavior and its imaging characteristics. It also demonstrates that the microcolumn imaging system provides a convenient vehicle for observations with SEM and other analytical methods,including GC, IR and TA. 

Effect of the pore diameter on the sensitivity and Dmax was also noticed (Figure 6). However, such an effect may be connected to a difference in thickness, which was also measured. Lower sensitivity and a higher Dmax were observed with thicker samples (Figure 7). Due to the direct correlation between membrane thickness and microcolumn depth, these results provide additional evidence of the bulk-responsiveness in the microcolumn imaging system. 

Figure 3. Reciprocity behavior of the microcolumn imaging system.

Photographic behavior of the microcolumn imaging system parallels the microencapsulated system in many respects. Microcolumn provides a convenient sampling format for application of the multi-technique approaches in addressing the interdependence of the imaging characteristics, curing conditions, and the structure of the polymer formed. 

Figure 2. Imaging process using microcolumn substrate. A-exposure, B-imaged sample, C-pressure development, D-final images on the receiver.

To obtain a final image both microencapsulated and microcolumn media were similarly developed using identical pressure rollers, receiver, and glossing step at 150°C for 1 min. 

The amount of extractable monomer and unreacted double bonds as a function of exposure were estimated using methods described above on the ITX system embedded in PC microcolumn membrane and exposed for 128 s at the illumination I = 1.29 mJ/cm s in the band width of 325-410 nm. In Figure 10 such data are compared to the color density change on the transferred image. A rather high conversion was determined in the sample exposed to the full intensity level available. 

Figure 6. Photographic shoulder speed and final Image color density vs. pore diameter for PC microcolumn membranes.

Figure 9. SEN images of polymer formed inside the microcolumn at corresponding intensity levels indicated by A and B in Figure 8.

The diamond growth can also be patterned to produce microelectrode array structures [18,19]. Several possible microstructures are possible, such as microbands, microdiscs, and microcolumns. Micropyramids are another microstructure that can be produced, and an image of such an array is shown in Fig. 5. The SEM image reveals a monolithic diamond-tip array. The tips are ca. 2 pm in base diameter and are equally positioned over the surface with a spacing of ca. 5 pm. 

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