The balance spring is etched out of a thin silicon wafer using a photolithographic technique, similar to that used for microelectronic chips, so its exact shape and thickness can be more carefully controlled than with metal.
The agency is gathering information from 11 major banks about their activities involving repos, an accounting technique that Lehman used to move billions of assets off its balance sheet each quarter end, and which the examiner claims deliberately masked the true nature of its leverage.
The degree to which this technique can fulfil its promise to lower CO2 and provide a sustainable fuel source depends crucially on the balance of energy it requires and the energy it stores.