A solid way to keep cool Refrigeration relies on vapor compression that is noisy, takes up space, and is mechanically complex. Solid-state cooling requires changing an external field to drive cooling, but devices produced so far have not been efficient enough for practical applications. Ma et al. constructed a lightweight and flexible device using a thin electrocaloric polymer film, where toggl...

Optoelectronic devices such as vertical cavity surface emitting lasers (VCSEL’s) generate large heat power densities on the order of 100’s of Wlcd . A novel device structure consisting of a two-stage monolithically integrated thin film thermionic and thermoelectric cooler is proposed to accommodate these cooling requirements. By optimizing the geometry of each stage, improved heat spreading can...

The production of machine parts usually ends with some kind of a heat treatment. A proper heat treatment, like quenching, provides increased surface hardness, which improves wear resistance. The quenching process must be fast to achieve the required hardness, but not too fast to prevent surface damage. Monitoring of the quenching process in real time, and an appropriate control can improve the ...

Recently, there has been great interest in "ultrastable" glasses formed via vapor deposition, both because of emerging engineering applications of these materials (e.g., active layers in light-emitting diodes and photovoltaics) and, theoretically, as materials for probing the equilibrium properties of glassy materials below their glass transition, based on the conjecture that these materials ar...

Dielectric film with ultrahigh thermal stability based on crosslinked polyarylene ether nitrile is prepared and characterized. The film is obtained by solution-casting of polyarylene ether nitrile terminated phthalonitrile (PEN-Ph) combined with post self-crosslinking at high temperature. The film shows a 5% decomposition temperature over 520 °C and a glass transition temperature (Tg) around 38...