Using Multiplexed Electrosprays To Manipulate Fluids and (soft) Materials

The cone-jet electrospray has revolutionized the field of mass spectrometry but, despite the unique ability of this device to produce quasi-monodispersed particles in a phenomenal size range down to the nanoscale, it has not been applied to other fields, except for small scale proof-of-concept demonstrations. The primary reason for the lack of widespread use is the low flow rate at which the spray is dispersed. Using fluid mechanics and electrostatics, we a) developed criteria for compact multiplexing to increase flow rate drastically, b) microfabricated systems with high packing densities (1.1 10⁴ sources/cm²), reducing the cost per electrospray source, and c) demonstrated successful operation of these devices in the synthesis of (soft) materials (e.g., polymer nanoparticles of controlled shape for drug delivery and battery materials) and in microchip cooling. I will review design criteria and applications.