While Sigurd came to conduct research and to teach, he also took up the mission of rebuilding Princeton’s strength in solid-state electronics. He helped this section of the Department of Electrical Engineering attain an outstanding national and international reputation. A hands-on semiconductor fabrication lab that he developed has for 25 years been taken by every sophomore in electrical engineering at Princeton, and by many undergraduate summer researchers and Ph.D. students. Alumni rate the lab as the best in their entire curriculum. He has a long history of encouraging women to pursue careers in science and engineering. Over the past decade, his research group, from undergraduate research advisees to postdocs, has been about 50 percent women, at least double the department average, and former members are now themselves faculty on three continents. When working on hydrogenated amorphous silicon in the 1980s, Sigurd discovered the defect pool, a subtle but conceptually important manifestation of thermodynamic equilibration in an amorphous material. Later on, with fundamental experiments conducted in the 1990s, he helped lay the foundations of flexible electronics. By wrapping thin-film transistors of amorphous silicon on a metal foil around a pencil, he presented the forerunner of today’s curved display screens. The discovery of elastically stretchable electrical conductors, made in his laboratory in the early 2000s, enabled making skin-like electronics. By virtue of their mechanical and electrical biocompatibility, such devices are beginning to add a new research dimension to neuroscience, and they raise hopes for clinical advances in the restoration of neural functions. In the current decade, the 2010s, he has enjoyed unique research collaborations with his colleagues James Sturm and Naveen Verma. By ranging from materials to systems, this joint enterprise is laying the broad foundation for advanced high-performance electronic surfaces.

Sigurd Wagner is widely considered the father of the field of flexible and stretchable electronics. Award citations speak of “groundbreaking research, both fundamental and applied, on amorphous semiconductors as well as chalcopyrites” (2009 Sir Nevill F. Mott Lecture Award, 23rd International Conference on Amorphous and Nanocrystalline Semiconductors) and “pioneering research on flexible and stretchable large-area electronics, and comprehensive study of the mechanical behavior of the same, which will be applied to various products in the near future” (2014 International Thin-Film Transistor Conference, 10th Anniversary Prize). Sigurd is a fellow of the American Physical Society, a fellow of the Institute of Electrical and Electronics Engineers, a corresponding member of the Austrian Academy of Sciences, and an Alexander von Humboldt Foundation Senior Fellow. From Princeton, he received a 2014 Graduate Mentoring Award.