In the oil exploration process, drilling toward a potential reservoir is interrupted with periodic sampling ("logging") of the physical environment at the bottom of the well. Instrumentation for these measurements are enclosed in a cylindrical steel shell, called the "tool", which is sent miles under the Earth's surface to record data and collect samples. The dimensions of a typical tool are 12 m in length and 10 cm in diameter. The tool descends through mud, and is subjected to temperatures near 400°F, pressures of 20,000 psi, in addition to variable magnetic fields and radioactivity. Currently, power for the instrumentation is delivered through the cable to which the tool is attached. Schlumberger is interested in developing energy-harvesting technologies to collect energy from various sources and to provide this power locally to the instrumentation. A group of Olin students and faculty have been working with Schlumberger on this project since January 2006. The energy storage options available have been explored, along with an understanding of the dominant physical forces acting on the tool as it descends. This project requires skills from all fields of engineering. Mechanical design skills are needed to design the hardware to pull energy from the environment. Mechatronics skills are needed to convert this harnessed energy into a form which can be stored locally. Electronics skills are needed to careful design circuitry that provides the power to the instrumentation efficiently. Further, all of these systems need to work together as efficiently as possible.