For more than three decades, he has conducted pioneering research work in HCI and is internationally recognized as the “founding father” of the field of Design for All and Universal Access, having introduced in the international literature in the '90s new concepts, methods and tools. He has published more than 550 articles in scientific archival journals, proceedings of international conferences and workshops related to the fields of his expertise.
He has been engaged as the Prime Investigator and Scientific Responsible in more than 100 European Commission and nationally funded R&D projects, RTD contracts and subcontracts in areas of his competence. He is the Scientific Responsible of the Registry of .gr (since 2004) and .ελ (since 2015) Domain Names, a department of ICS-FORTH responsible for the operation and technical coordination of the .gr and .ελ top-level domain name spaces.
Since the ‘80s, he has been actively contributing to the European Commission RTD Policy on Information Society, either as a member of EC experts’ committees, or as National Representative in Management Committees of successive RTD Framework Programmes in the field of Information and Communication Technologies (ICT). He was the Scientific Coordinator of the EC Coordination Action InterLink (2006-2009), which addressed large-scale, basic research problems in 'software intensive systems and new computing paradigms', 'ambient computing and communication environments' and 'intelligent and cognitive systems', under a human-centred perspective, and defined joint basic research agendas for world-wide cooperation in these domains.
As Founder and Head of the Ambient Intelligence Programme of ICS-FORTH, Prof. Stephanidis is coordinating since 2005 multidisciplinary and cross-thematic activities with the aim of conceptualizing, designing and developing in vitro, and deploying in vivo, pioneering, innovative technologies and applications for Smart Environments, capable of "understanding" and proactively addressing individual human needs, following a human-centred approach. Examples of such outreach activities include the installation of interactive systems in public places, where hundreds of thousands of visitors use them.
In 2010, Prof. Stephanidis was elected member of the Informatics Section of the Academia Europaea, the European Academy of Humanities, Letters and Sciences.
During 2008 - 2009 he served as member of the Sectorial Scientific Committee of Informatics of the National Council for Research and Technology, Hellenic Ministry of Development. From March 2014 to May 2016, as member of the Member of the National Council for Research and Technology (NCRT), Hellenic Ministry of Education. Since January 2017, he is President of the Council for Research and Innovation of the Region of Crete.