Scientists at Bristol University have used ultrasonic waves to impose patterns on doped water droplets, in research that has implications for drug delivery and clinical diagnostics.
Published in the journal Nature Communications, the work details how chemically encoded water droplets were patterned into a two dimensional array. An acoustic standing wave is used to shape the droplets, which are contained within a water-filled chamber. By altering the composition of the constituent liquid and engineering the acoustic field, the team was able to produce highly uniform arrays of droplets arranged in square lattices.
“As the coavervate droplets are formed they are gripped by the ultrasonic forces and patterned,” explained Professor Bruce Drinkwater, head of Bristol’s Ultrasonics and Non-Destructive Testing (UNDT) research group.
“The uniformity of the droplets is amazing. I’m convinced this technology will have many applications in the next generation of lab-on-a-chip applications.”
The size, spacing and surface-attachment properties of the droplets can be manipulated. They can also be loaded with proteins, enzymes, DNA, polysaccharides, nucleotides, nanoparticles or microparticles, and used in small-scale chemical reactions. According to the research team, the droplet arrays could act as a new type of analysis tool for drug discovery, clinical diagnostics and protein crystallization.
“The acoustic patterning method significantly extends the scope of the current micro-array technologies,” said Prof Stephen Mann from the Bristol Centre for Protolife Research.
“We should now be able to develop devices capable of sustaining chemical signals between the droplets as well as enabling spatial and temporal responses to changing conditions in the external environment. This will allow us to exploit the acoustically trapped liquid droplets as a 2D community of spatially organised membrane-free protocells.”