University of Notre Dame College of Engineering

RESEARCH GALLERY

AC electrospray of ethanol at 40 kHz and 4 kVpp. Note the characteristic angle of the cone is approximately 12 degrees, which is notably different than the 49 degrees associated with the DC electrospray Taylor cone. The cone also continuously grows until it destabalizes over a time scale of many seconds. For more information, see:
N. Chetwani, C. A. Cassou, D. B. Go, H.-C. Chang, "High-frequency AC electrospray ionization source for mass spectrometry of biomolecules," J. Am. Soc. Mass Spectrom, vol. 21, pp. 1852-1856, 2010. (doi)
N. Chetwani, C. A. Cassou, D. B. Go, H.-C. Chang, "Frequency dependence of AC electrospray ionization mass spectrometry," Anal. Chem., vol. 83, pp. 3017-3023, 2011. (doi)
S. Maheshwari, "Anomalous Microfluidic Behavior Near Singular Interfaces," Ph.D. Thesis, 2008. (link)

 

AC electrospray of ethanol at 100 kHz with nebulizing gas - 10000 frames per second. Note the axial ejection of distinct droplets as opposed to the expanding droplet plume produced by DC electrospray.

Rapid aerosolization of tap water using a paper-fed surface acoustic wave (SAW) device. For more information, see:
J. Ho, M. K. Tan, D. B. Go, L. Y. Yeo, J. R. Friend, H.-C. Chang, "A paper-based microfluidic surface acoustic wave sample delivery and ionization source for rapid and sensitive ambient mass spectrometry," Anal. Chem., vol. 83, pp. 3260-3266, 2011. Accelerated Article (doi)