Over the years, many researchers have sought to convert heat to electricity directly, without benefit of turbine or generator. Now, professor Peter Hagelstein of MIT's Department of Electrical Engineering and Computer Science, working with Yan Kucherov of ENECO Inc., reports a device based on semiconductor technology that achieves this goal. Their approach builds on earlier thermionic "vacuum gap" design where electrons boil off a cathode, traverse the gap, and are absorbed into a colder anode, to convert heat to electricity. However, operating temperatures greater than 1,000C limited the usefulness of such scenarios. The new strategy improves performance by replacing the traditional vacuum gap with a multi-layer semiconductor structure. These solid-state conversion devices operate between 200 and 450C–typical temperatures for waste heat recovery. Hagelstein suggests that captured heat lost through automobile engine exhaust might be converted into electricity. The researchers' work has been sponsored by ENECO and DARPA. Patents have been applied for in the U.S. and Europe. For more information, contact Elizabeth Thomson at the MIT News Office, firstname.lastname@example.org.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This radio show will show what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.