Mark J. Nahnsen

  • One North Wacker Drive
    Suite 4400
    Chicago, IL 60606-2833

Mark J. Nahnsen is a partner in the Chicago office of Barnes & Thornburg LLP and a member of the Intellectual Property Department. Mr. Nahnsen represents and counsels individuals and corporations on patent, trademark, copyright and trade secret matters and on foreign and domestic patent and trademark protection.

His practice focuses on patent and trademark counseling, intellectual property licensing, preparing and prosecuting domestic and international patent and trademark applications, the development and maintenance of patent and trademark portfolios and intellectual property litigation. His practice also encompasses patent infringement and invalidity analysis, product clearance and legal opinion work. Mr. Nahnsen also is experienced in negotiating contracts and intellectual property licenses.

He represents large companies with significant market presence in the automotive, juvenile safety, and packaging industries. His technical focus is on mechanical engineering, including fluid mechanics, emission controls and complex mechanical systems. He provides counseling to a variety of clients in the manufacturing and high tech industries.

Mr. Nahnsen has experience in virtually all phases of intellectual property litigation in the federal courts over a broad range of technologies including polymer materials, construction equipment, high-speed packaging machinery and electronic devices.

Mr. Nahnsen often speaks to various audiences on topics relating to intellectual property. He is admitted to practice in the state of Illinois and before the U.S. District Court for the Northern District of Illinois and the U.S. Court of Appeals for the Federal Circuit.

Mr. Nahnsen received his B.S. in engineering from Purdue University and his J.D. from The John Marshall Law School. He is a member of the Chicago, Illinois State and American Bar Associations as well as the American Intellectual Property Law Association. Mr. Nahnsen is an automotive enthusiast and enjoys restoring vintage and classic cars.