The application of silicon sol-gel technology to forensic blood substitute development: Investigation of the spreading dynamics onto a paper surface

- This work assesses the spreading dynamics of forensic blood substitutes on paper.
- The Scheller and Bousefield correlation was used with an effective viscosity parameter.
- Physical properties of three candidate sol-gel materials are presented and discussed.
- A final recommendation on one sol-gel material was made for dripping simulation.

This work investigates the spreading dynamics of three candidate sol-gel solutions, of ranging viscosities, surface tensions and densities, and compares them with water and two commercial blood substitute products. Droplets were created with different sizes (10 to75 μL) and impact velocities (1.4 to 6.0 m/s) to strike 176 gsm cardstock. Over 2200 droplets were created using the six different fluids and their final dried stain diameter was measured. Droplet spread was plotted using the Scheller and Bousfield correlation and uses effective viscosity as a parameter for non-Newtonian fluids. Comparing the results to an expected whole human blood range validated the spread of the candidate FBS sol-gel material in passive drip bloodstain pattern simulation. These findings complement the practical application of the material as a safe substitute for demonstrating droplet spread under controlled conditions on hard paper surfaces.