SAWN Ion Source
We have developed a novel planar method to form ions for mass spectrometry by surface acoustic wave nebulization (SAWN). Extensive preliminary results have demonstrated several advantages to this method in comparison to electrospray ionization (ESI) and matrix assisted laser desorption (MALDI). First, unlike ESI, a high voltage electric field is not required eliminating the chance of redox reactions occurring. Second, there are no capillaries to be clogged and the planar geometry of the SAWN platform allows for the integration of complex fluid handling by droplet-based microfluidics (DMF). Third, analysis with thermometer ions has shown that SAWN is softer (i.e. less fragmentation occurs) than both ESI and MALDI.
The amount of sample required for mass spectrometric (MS) analysis is frequently determined not by instrument sensitivity but by the ability to isolate, prepare and deliver trace analytes. Losses during conventional sample preparation and challenges in working with small volumes compound the problem.
In addition to developing AC-driven copper-clad polyimide devices, we have recently developed a new technique for the manufacturing of DMF devices. This technology is in its infancy but promises to deliver an even cheaper and higher throughput manufacture of devices.