Electroactive micro and nanowells for optofluidic storage

This paper reports an optofluidic architecture which enables reversible trapping, detection and long term storage of spectrally multiplexed semiconductor quantum dot cocktails in electrokinetically active wells ranging in size from 200nm to 5 mu m. Here we describe the microfluidic delivery of these cocktails, fabrication method and principal of operation for the wells, and characterize the readout capabilities, storage and erasure speeds, internal spatial signal uniformity and potential storage density of the devices. We report storage and erase speeds of less than 153ms and 30ms respectively and the ability to provide 6-bit storage in a single 200nm well through spectral and intensity multiplexing. Furthermore, we present a novel method for enabling passive long term storage of the quantum dots in the wells by transporting them through an agarose gel matrix. We envision that this technique could find eventual application in fluidic memory or display devices. (C) 2009 Optical Society of America