etrema products, inc. (etrema) is an iowa corporation engaged in the manufacture and distribution of smart material alloys, devices using such alloys, and engineering services. etrema holds the exclusive license for processing an advanced smart material called etrema terfenol-d â® ('terfenol-d'). etrema was formed in 1987 to develop, manufacture and market terfenol-d. currently etrema has the only facility in the world with the ability to produce commercial quantities of high quality of terfenol-d.