European and Dutch patent attorney
Andries (Ard) Ellens (PhD)
European and Dutch patent attorney UPC representative


Ard Ellens studied chemistry at the Utrecht University (Netherlands), with specialisations at the University of Leuven (Belgium) and Delft (Netherlands). He obtained a PhD in the field of solid state chemistry at the Utrecht University. After his PhD, he worked as post-doc at the University of Berne in Switzerland. Ard Ellens continued his career as research scientist at OSRAM in Munich (Germany) where he performed R&D in the field of luminescent materials for UV lamp or LED applications. During this period, he gained interest in intellectual property (IP) and decided to switch to IP consultancy. In 2001 Ard Ellens started as trainee at a top tier patent firm in the Netherlands and became Dutch patent attorney in 2004, European patent attorney in 2005, and associate partner in 2008. In 2011, Ard Ellens was one of the founders of the patent firm Ellens & van Essen B.V..

Since 2024 Ard is also a registered representative for the Unified Patent Court (UPC) following Rule 12.1 of the Rules on the EPLC, also known as the “Grandfather Clause”.

Expertise as patent attorney

Ard Ellens has experience in patent drafting, prosecution and opposition. Furthermore, Ard Ellens gives strategic IP advice and provides IP workshops/lectures to R&D scientists. His areas of practice over the years as patent attorney include chemistry, physics and mechanics, especially themes that are at the interface of these disciplines, such as  inorganic/solid state chemistry, (heterogeneous) catalysis, (inorganic) materials, luminescent materials, optics, optical analysis, lanthanide spectroscopy, measuring techniques, lighting systems, (optical) medical devices, micro fluidic devices, foods & beverages, chemical processes, renewables, torrefaction, (bio)reactors, membrane applications, and water purification. Ard works for start-ups, SME’s, research institutes, consultancy and engineering firms, and multi-nationals.


Ard Ellens enjoys the lively practice of working in completely different technology areas and responsibly creating and enforcing the best proposition for a client. He appreciates advising all kind of clients, from start-ups to multinationals, and likes teamwork.

Publications and Memberships

Ard Ellens is (co)author of a dozen of scientific publications and (co)inventor of 14 patent applications. Furthermore, he is author of a number of papers in Managing Intellectual Property, amongst others devoted to the topic of divisional applications in Europe. He is member of the Royal Dutch Chemical Society (KNCV), the Dutch Patent Attorney Association, and the Institute of Professional Representatives before the European Patent Office (EPI). Further, Ard Ellens is involved in the training of Dutch patent attorneys (SBO/CPO).

+31 317 46 55 15