Electron Sandwich (IMAGE) Hokkaido University Caption Conceptual drawing of the superlattice in which spread electrons are confined to a narrow space to enhance thermoelectric conversion. Credit Hokkaido University Usage Restrictions This image is copyrighted and can be used for reporting this press release if properly credited. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.