Figure 1. Topographical scans of the top and side of one 4 µL
bloodstain at varying times since deposition up to 4 weeks. The scans
show the height (μm) against the X-distance (μm) on the plate. The
corresponding height profile is taken from the vertical/horizontal slice
of each scan over time is also shown (bottom right).
3.2 Short-Term
Experiment
Topographical scans for the short-term experiments indicate that in the
first ~15 minutes, the bloodstain changes from a liquid
sessile drop to a soft-solid as more of the bloodstain can be detected
by the profilometer (Figure 2). After the bloodstain had dried, the
formation of the rim was observed, indicating that the majority of the
RBCs had moved to the outside of the bloodstain (Figure 2, 15 minutes).
The formation of cracks occurred between ~20-30 min, and
after ~35 minutes after deposition, there were no
significant visual changes in the subsequent scans (Figure 2).