In this thesis, we present a new platform for remotely powered and monitored, untethered, wireless electronic devices made at the size scale of single cells: optical wireless integrated circuits (OWICs). This work details the first cell-scale platform demonstrating parallel produced, stand-alone, untethered electronic devices that are powered and communicate optically. Using this platform, we produce OWIC sensors as small 8 μm x 65 μm x 100 μm (0.00005 mm^3), representing more than a 10,000-fold reduction in volume from the mm^3 scale typical of current remotely-monitored wireless technologies. Methods are detailed in this thesis to produce devices in parallel, without requiring any packaging or assembly steps on a per-device basis, yielding approximately 10,000 devices per square inch. To use these tiny devices in a variety of environments, new methods are presented for precise manipulation and delivery OWICs. We demonstrate the potential of OWICs by creating proof-of-concept sensors that remotely measure voltage, temperature, pressure, and solution conductivity in a variety of environments, including experiments conducted in microfluidics and the brain of a living mouse. We further present more sophisticated CMOS-integrated OWICs developed for monitoring neural signals. Finally, we demonstrate the potential of the platform for mobile microrobotics by presenting an all optical, cell-sized walking microbot with all dimensions less than 100 μm.