Evaluation of a drop-on-demand micro-dispensing system for development of artificial fingerprints
Jessica L. Staymates, Matthew Staymates, John Gillen
Precision micro-dispensing is a growing technique that has many applications in the scientific and additive manufacturing communities. Piezoelectric inkjet printing is capable of accurately dispensing exceedingly small volumes of low-viscosity solutions, while other techniques exist that can deposit larger volumes of highly viscous materials. Here we describe a method for dispensing viscous materials, including the oily substance found in human fingerprints, known as sebum. Many efforts are currently underway to prepare test materials to verify the operational condition of trace detection instrumentation. Since trace contamination is commonly spread via fingerprints, the ability to include these fingerprint substances in the prepared test materials would be a valuable step towards producing a realistic artificial fingerprint. The printing technology described in this work is shown to effectively dispense artificial sebaceous materials in a repeatable manner using a drop-on-demand ejection approach. Ultraviolet-visible spectrophotometry and microgravimetry were used to verify the sebum mass loadings of the samples.