structure features in each test well crystallization was carried out with three different droplet volumes namely 5 10 and 15 microliters in all cases drying was carried out at room temperature and at least 20 minutes was allowed before testing each test well was imaged twice in plan view with a scanning electron microscope sem once at low resolution u00d7 45 to view the whole well and once at high resolution u00d7 5000 to image the micro structure after crystal formation each test well was imaged again at the low resolution to show the crystal for each test well there are therefore 5 images in total since for each test well crystal formation was carried out using three different droplet volumes as already mentioned fig3 4 5 and 6 show sem images from the tests for the 16 test wells where the numbering follows that shown in fig2 each figure shows four test wells one per column with the 5 images per test well being arranged in 5 rows in the tests where the crystal has not formed centered on its well the crystal images are labeled u201c spot outside well u201d which is referred to as a failure in the following as mentioned well 01 fig3 column 4 and well 13 fig4 column 2 are control examples with no micro structure for control well 01 the crystal formed with the 5 u03bcl droplet is.