A biomimetic mass-flow transducer utilizing all-optofluidic generation of self-digitized, pulse code-modulated optical pulse trains

We present a new mass-flow transducer producing responses in the form of optical pulse trains that are encoded with information on the strength and position of the stimulus. We implemented the self-digitization and encoding capabilities all-optofluidically, without involving external electronics, by integrating one optical fiber cantilever with multiple polymer optical waveguides on a microfluidic platform. The transducer can also be configured to respond only to transitional stimuli. These features closely mimic the rate-coding, action potential labeling, and rapid adaptation processes observed in biological mechanoreceptors and allow multiple transducers to transmit signals over a single, shared channel. We fabricated the transducer using polymer-based soft-lithography techniques. Its characterization confirmed the stimulus strength-dependent generation of optical pulses and the feasibility of multiplexing 2^n-1 to 2ⁿ transducers using n waveguides.