Marty Gregg leads the nanoscale ferroelectric activity in Queen's University Belfast. In the past, he had research activities on ferroelectric thin films and superlattices grown by Pulsed Laser Deposition (1997-2005), and in the characterisation and understanding of well-controlled nanoscale ferroelectric entities cut from high purity bulk crystals using Focused Ion Beam milling (2004-2014). Most recently, he has been directing particular attention towards understanding and controlling domain wall properties, both in bulk single crystals and in single crystal films and lamellae. This is rapidly becoming an area of great excitement, as it is becoming clear that ferroelectric domain walls are functional materials in their own right, with properties different from the domains that they surround.

Microscopy is a critical component in nanoscale ferroelectric research and Marty has been heavily involved in electron, ion and scanning probe techniques for most of his career. He has rejuvenated the transmission electron microscopy (TEM) and focused ion beam (FIB) microscopy capability of the university twice: first in 2000 through £1.5M of EPSRC funding for a Tecnai F20 TEM and FEI FIB and again in 2017 through £1.8M of EPSRC funding for a FEI Talos TEM and two Tescan FIBs. He has twice been the Director of the Electron Microscopy Facility (2000-2010 and 2015-2020).

Marty was the Director of Research for the Centre for Nanostructured Media (CNM) for over five years (2015-2020), Director for Research for the School of Mathematics and Physics, for four years (2020-2024) and is now acting as the Head of School (2024-present). He also had a brief stint, acting as Dean of Research for the Faculty of Engineering and Physical Sciences to cover for illness in 2021.

He is a Fellow of the Institute of Physics and was elected to the Royal Irish Academy in 2018. In 2025 he was elected to a Fellowship of the American Physical Society; he is currently serving a second term on the EPSRC Strategic Advisory Team (SAT) for Physical Sciences and Advanced Materials.