Sullivan developed a process to fabricate transformers which uses methods similar to integrated circuit fabrication techniques. He studies these devices with a focus on designing and optimizing performance in a power application such as battery-powered portable electronic equipment. The smaller the power source, the more important efficiency becomes for battery life. In other words, relative energy waste is bigger for smaller devices. So many of the principles involved in higher power devices can be applied on a smaller scale, with even some additional challenges.
Fluorescent lamps can be more efficient using a high-frequency power supply.
Achieving low cost and high efficiency is always a challenge, but because of the non-linear nature of the lamp, its circuit design is even more challenging. Yet another application of Sullivan's research is the speed control of motors. This is an issue for motors in industrial use, and also for consumer products such as electric vehicles and refrigerators. Better speed control for a vehicle would optimize performance, while a refrigerator could be quieter and more efficient and maintain its temperature at a more precise and constant level. Like his research, Sullivan's teaching benefits from an interdisciplinary approach.