This article describes a new procedure for generating and transmitting a messagesa sequence
of optical pulsessby aligning a mask (an opaque sheet containing transparent “windows”) below a
microfluidic channel in which flows an opaque continuous fluid containing transparent droplets. The optical
mask encodes the message as a unique sequence of windows that can transmit or block light; the flow of
transparent droplets in the channel converts this message into a sequence of optical pulses. The properties
of the windows on the mask (e.g., their size, wavelength of transmittance, orientation of polarization)
determine the information carried in these optical pulses (e.g., intensity, color, polarization). The structure
of a transmitted signal depends on the number and spacing of droplets in the channel. Fourier transformation
can deconvolve superimposed signals created by the flow of multiple droplets into the message that a
single droplet would transmit. The research described in this contribution explores a new field at the
intersection of chemistry, materials science, and information technology: infochemistry.