Decontamination of blood soaked electronic devices using ultrasonic technology

With advancements in technology allowing for the miniaturization of consumer electronics, criminal investigations of all types frequently involve the forensic examination of electronic devices, such as cellular telephones, smartphones, and portable flash memory; in some extreme, violent cases, these devices are found covered in blood. Due to the complexity of such devices, standard operating procedures for the complete removal of blood had not previously been established by the Royal Canadian Mounted Police prior to this study. The electronics industry has adopted the use of the ultrasonic cleaner for sanitizing printed circuit boards (PCBs) by removing residues and contaminants. High frequency sound waves created by the machine penetrate and remove dirt and residues; however, early research during the 1950s recorded these sound waves breaking the internal bonds of integrated circuit chips. Experimentation with modern ultrasonic technology was used to determine if internal components were damaged, as well as if ultrasonic cleaning was the most suitable method for the removal of dried and liquid blood from a PCB. Several disinfectant solutions were compared against the 0.5% Triton® X-100 detergent solution in the ultrasonic cleaner, including: 10% sodium hypochlorite bleach, 85% isopropyl alcohol, and Conflikt® disinfectant spray. The results not only demonstrated that the ultrasonic cleaner did not damage the vital memory chip on the PCB, but also, with the assistance of Conflikt®, was able to remove all traces of blood as indicated by Hemastix® reagent strips. Of five methods experimented with, two cycles of ultrasonic cleaning followed by sanitization with Conflikt® proved to be the only procedure capable of removing all traces of blood, as confirmed with both Hemastix® reagent strips and the hemochromogen test.