ACElecrospray
Our AC electrospray, which functions on a distinctly different mechanism from DC electrosprays, can be used for a broad array of applications ranging from drug encapsulation to being the front-end for a mass spectrometer. The electrospray, when used with a biodegradable polymer, is used to make micron-sized coated particles as well as monodisperse coated nanoparticles. As the pictures and video clips illustrate, this is one of our most exciting projects that promises to make a major commercial impact.
A Scanning Electron Microscope picture of micron-sized biodegradable particles.
DC Taylor cone for ethanol in air at 3000 V
Four consecutive images of AC ethanol electrospray in air at a high frequency of 70kHz and V rms of 1750 V. The frames are about 0.2 milliseconds apart and the captured event represents one drop ejection in a rapid sequence. There is a long interval between such series of ejections. The conic tips of DC and low-frequency AC sprays are replaced by a rounded one. Before ejection, the tip region elongates and expands as the neck shrinks until a large-micron drop is ejected when the neck pinches.
A biodegradable fiber made by the AC electrospray may be used for sutures.
This biodegradable fiber network may be used in conjunction with drugs to accelerate the growth of new skin on burns or cuts.
A Scanning Electron Microscope image of a biodegradable fiber and monodisperse nanometer-sized biodegradable particles.
- Droplet Ejection. Four drops are ejected by the AC electrospray in real time.
- Unstable Droplet Ejection. The droplet ejection mechanism is frequency and voltage dependent. This clip illustrates unstable droplet ejection and a microjet can clearly be seen.