A 3.1 nJ/bit pulsed millimeter-wave transmitter, 300μm by 300μm by 250μm in size, designed in 32-nm SOI CMOS, operates on an electric potential of 130mV and 3.1nW of dc power. These achieved power levels and potentials are comparable to those present across cellular and intracellular membranes. Far-field data transmission at 33 GHz is achieved by supply-switching an LC-oscillator with a duty cycle of 10^-6. The time interval between pulses carries information on the amount of power harvested by the radio, supporting a data rate of ~1bps. The inductor of the oscillator also acts as an electrically small (~λ/30) on-chip antenna, enabling the extremely small form factor.