Dutch Scientists Use Lasers to Reduce Splashing in Needle-Free Injections
The technique is fairly straightforward. These guys fill a capillary with liquid and focus a laser pulse onto one end. This rapidly heats a portion of the liquid causing it to evaporate suddenly and send a shock wave through the tube. This pushes accelerates the rest of the liquid forcing it out of the capillary at high speed.
The tube and rate of heating is designed to generate shockwaves that focus this microjet so that its tip is just a few tens of micrometres across, smaller than a mosquito’s proboscis. When the liquid hits the skin at this speed, the microject easily penetrates, delivering a precise volume of liquid to the tissue beneath. And all this happens with little, if any, splashing.
Tagawa and co have tested their system on gelatin covered with synthetic skin and say it works well as the images above seem to testify. “The results…take needle-free injections a step closer to widespread use,” they say.
(via Needle-Free Injections Perfected Using Supersonic Liquid Microjets - Technology Review)