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Shape-memory biomaterials for medical applications

The doctoral dissertation of MSc (Tech) Kaarlo Paakinaho explores biomaterials that are capable of changing their shape in response to specific stimuli. They have the potential to simplify and speed up surgical procedures.

For his dissertation research, Researcher, MSc (Tech) Kaarlo Paakinaho from Tampere University of Technology (TUT) developed a biomaterial that can be programmed to respond to a specific stimulus by changing its shape. The transformation may be triggered, for example, by exposure to an aqueous environment at 37 degrees Celsius.

“Although the material is stiff and strong, it can be induced to change its shape without any external energy. Unlike existing shape-memory materials, implants made of this polymer don’t have to be preheated before they are placed inside the human body, so no thermal tissue damage can occur,” says Paakinaho.

The technology and methods presented in the dissertation are ready to undergo preclinical testing and are likely to streamline surgical processes. For example, when shape-memory nails are used, the material can be programmed to expand inside the human body and thereby effectively adhere to the surrounding tissue. Thus, it would no longer be necessary to create threads in the patient’s bone that match those found on the implant.

Public defence of a doctoral dissertation on Friday, 9 August

The doctoral dissertation of MSc (Tech) Kaarlo Paakinaho titled “Processing Derived Control of Hydrolytic Degradation and Generation of Shape-Memory in Lactide Copolymers” will be publicly examined at the Faculty of Computing and Electrical Engineering of Tampere University of Technology (TUT) in room RG202 in the Rakennustalo building (address: Korkeakoulunkatu 5, Tampere, Finland) on Friday, 9 August 2013 at 12:00.

The opponent will be Principal Scientist, Dr. David Eglin (AO Research Institute Davos, Switzerland). Professor Minna Kellomäki from the Department of Electronics and Communications Engineering at TUT will act as Chairwoman.

Kaarlo Paakinaho (34) works as a researcher at the Department of Electronics and Communications Engineering of TUT. He is part of the Electronic and Biomaterials and Manufacturing (EBMM) research group. 

Further information: Kaarlo Paakinaho,, tel. +358 40 849 0975

The dissertation is available online at:

News submitted by: Anna Naukkarinen
Keywords: science and research, kaarlo paakinaho, doctoral dissertation