Andy Downard
Andy is a graduate student in the Flagan Lab at Caltech in Pasadena, California, USA. His research focuses on using electric fields with two-dimensional flows to continuously separate charged particles in air and water.
The current standard for aerosol separations is the differential mobility analyzer (DMA), and the Flagan Lab contribution to CLOUD is a nano-radial DMA that has favorable transmission and resolution in the range of 1 to 10 nanometers. Standard DMAs utilize a nearly unidirectional flow with an orthogonal electric field to classify aerosols. The total price tag of a DMA, with a detector and the support equipment, is in the tens of thousands of dollars. When these instruments are taken onto airplanes, where space and weight are at a premium, they are the size of a large desktop computer and weigh an undesirably large 20 kilograms.
Andy is developing opposed migration aerosol classifiers (OMACs), which are a miniature, inexpensive alternative to DMAs. OMACs counteract displacement owing to the electric field with a crossflow, enabling the design of smaller devices that operate at low voltage. The Flagan Lab vision for this instrument is to develop pocket-sized integrated aerosol classifiers at a cost of less than a thousand dollars.