When the Department of Automatic Control and Systems Engineering (ACSE) at The University of Sheffield was looking for a way to accurately 3D print bioelectronic sensors, it requested support from Intertronics. The company provided mixing and dispensing equipment to enhance the consistency and quality of the mix, accomplish better printing definition, and reduce blockages in the nozzle of the 3D printer.
To enhance the way recovery from injury and the progression of neurological/musculoskeletal conditions are monitored, the ACSE team is developing a diagnostic glove that incorporates several flexible bioelectronic sensors. The sensors are formed from elastomers mixed with different conductive nano or micro particle compounds, such as graphite, platinum, and silver, which are 3D printed onto the glove’s material.
To dispense tiny amounts of material, the team employs an extrusion-based 3D printer. However, throughout dispensing, particle aggregates were forming, and particle distribution was being altered, causing material to clog in the nozzle. The team contacted Intertronics, who recommended Preci-Tip Precision Dispensing Tips. Their design has a streamlined conical fluid path that provides smoother, higher fluid flow rates and lower dispense back pressure when compared with the majority of standard dispensing tips, producing an improved accuracy and greatly reduced clogging. Their industry standard Luer Lock fitting meant they were compatible with the University’s existing equipment.
“The customer reported that the Preci-Tips worked well on their highly viscous silicones, they offered good flow, good fluid break off, and stopped agglomerations,” said Paul Whitehead, strategic accounts manager at Intertronics. “The results were better definition and a more reliable system, without blockages during the 3D printing process. However, further discussion revealed that they had challenges with the mixing of the filled polydimethylsiloxane (PDMS) mixtures.”
“The THINKY Mixer is a huge improvement on our previous process and means we can achieve consistent outcomes more quickly,” said Tom Paterson, postdoctoral research associate at The University of Sheffield. “We’ve removed the need for solvents, which removes a step from the process, improves health and safety, and removes the regulatory requirement to prove this compound has been removed. The mix quality is extremely good, the mixer doesn’t introduce air into the mix, and we’re making a substantial time saving.”