Coded corrugated microfluidic sidewalls for code division multiplexing

The transduction of a biological event into a readable electronic signal generally occurs as a result of modulation of amplitude of either an optical, electrical, or mechanical signal. Several limitations occur as a result of amplitude modulation, like limitation of sensitivity due to amplitude noise and difficulty of multiplexing. In the electronics industry, the modulation of frequency or phase of the signal is widely used and offers many advantages such as extraction of signals buried in amplitude noise, or detection of multiple codes on a single line, and several other advantages. Here we introduce a novel method involving the use of gratings in the sidewalls of microchannels for coding a signal in phase in addition to amplitude. The use of this technique allows for several advantages such as improvement in signal-noise ratio, and also allows for the possibility of using a single line for simultaneous multiplex measurement of biological events.