He is Chief Science Officer of SynAgile Corp. of Wilson, Wyoming, consults to Abbott Diabetes Care of Alameda, California, and is Ernest Cockrell Sr.

His 1973 paper with James J. Auborn established the feasibility of high energy density, high-voltage, non-rechargeable lithium batteries[1].

In 1944, following the Second Vienna Award, the Hungarian administration confiscated his family's property, and they were forcibly relocated along with more than 18,000 other Jews to the Kolozsvár Ghetto within the walls of the Iris Brickyard.

[12] In 1962-1963 he was a Post-doctoral Research Fellow at University of California, Berkeley and in 1963-1964 he was a Postdoctoral Member of the Technical Staff of Bell Laboratories in Murray Hill, New Jersey.

Heller was the first Chief Technical Officer of TheraSense and as of December 2021 continued to consult to Abbott Diabetes Care.

The world's most widely used FreeStyle Libre continuous glucose monitoring system of Abbott Diabetes Care was introduced in 2016.

Its subcutaneously implanted amperometric sensor utilizes concepts of  Heller's glucose concentration to electron current transducing electrically wired  glucose oxidase electrode maintaining a  constant sensitivity through a polymeric membrane that controls the inflow of glucose.4-8 Heller serves as Chief Scientific Officer of Synagile Corporation, a venture developing a continuous oral L-DOPA systems for managing advanced Parkinson's disease.

Heller showed in 1966 that the cause of radiationless relaxation of excited rare earth ions in solutions was energy transfer to hydrogen atom containing solvents that vibrate at high frequencies.

With the floating  titanium dioxide coated cenospheres, the residues of  coal combustion, he and colleagues catalyzed the sunlight assisted oxidation of thin films of crude oil on water (1992-1995),[21][22][23] then with Yaron Paz he made in 1993-1995 transparent titanium dioxide films on window glass that under  sunlight catalytically oxidized organic contaminants.

[5] The absence of leachable matter from wired enzyme electrodes enabled their use in the blood of animals and in their subcutaneous fluid.

[43] For his radiation-less relaxation studies in liquids, liquid lasers, primary lithium thionyl chloride battery, 10% efficient electrochemical solar cells and environmental photocatalysis, he was made in 1982 Guest Professor of the college de France; was elected to the U.S. National Academy of Engineering in 1987;[44] received the 1994 Chemistry of Materials Awards of the American Chemical Society; the 1995 Engineering Practice Award of the American Institute of Chemical Engineers; the 2015 Heinz Gerischer Prize of European Section of The Electrochemical Society; and was made in 1991an Honorary Doctor of Uppsala University in Sweden.