Integrated Low-Power Wireless Systems for the Next Generation of IoT, Sensors and Microrobots

The relentless pursuit of smaller, cheaper, and lower-power wireless electronics has driven the design of novel radio designs such as crystal-free radios, that o er a fully functional wireless node with minimal external components. At Berkeley, the Single-Chip Micro Mote (SCμM), a 3x2 mm, 4.2mg crystal-free 802.15.4 and BLE wireless SoC, was developed to make swarms of mm-scale microrobots a reality. This dissertation will begin by discussing SCμM in the context of system integration, including the challenge of accurate channel frequency tuning in the face of varying temperature and voltage conditions. By characterizing the RF frequency's dependence on voltage droop during transmission, we were able to compensate for the RF frequency shift, increasing SCμM's 802.15.4 packet payload from 10B to 125B while powered from a solar cell. Several integrated systems with SCμM at their core will also be discussed, including a wirelessly-actuated, solar-powered, quarter-sized, 286mg microrobot MEMS gripper for microrobotics; and a 244mg, 5x8mm BLE SCμM tag, which was used to track an Asian hornet|feats not possible with commercial o -the-shelf components. The dissertation will conclude with a look at how future crystal-free radios could be designed to address the inherent instability of power sources in low-power systems, potentially pushing the envelope for even smaller, cheaper, lower-power and more reliable wireless electronics.