Next generation ceramics boast multifunctional properties
The research group headed by Professor Erkki Levänen specializes on porous ceramic filters. A ceramic hot gas filter is displayed on the left and a liquid filter on the right.
Ceramics are a diverse group of materials that are used, among others, in the manufacture of catalytic converters and human spare parts. Modern-day ceramics display number of exciting functionalities, such as self-cleaning properties, which open up an even wider range of potential applications.
The Department of Materials Science at Tampere University of Technology has a long-standing reputation for pioneering research in the field of ceramic materials. The first project focusing on engineering ceramics was completed back in 1987 under the supervision of Emeritus Professor Tapio Mäntylä. At the same time, the department instigated collaboration with industrial partners, such as Tampella.
"We initially joined forces with industry to develop, for example, ceramic grindstones for pressure grinders. Afterwards we expanded our research on porous ceramics to include hot gas filtration. As we learned more about porous structures, we shifted our focus to semi-permeable ceramic membranes that were especially used to filter forest industry wastewaters," says Professor Erkki Levänen.
Materials for harsh environments
Ceramics are inorganic compounds made up of two or more elements, usually metal oxides, nitrides and carbides.
They offer superior resistance against heat, wear and abrasion and exhibit special electrical, magnetic and optical properties.
"Industrial ceramics are much harder than hardened steel. There really are no viable alternatives for ceramics, if you need a material that can withstand high temperatures and aggressive chemicals. Ceramics are chemically inert and therefore remain stable even in extreme conditions."
WHO: Professor Erkki Levänen
- He completed a master's degree in 1989, a licentiate degree in 1994 and a doctorate in 2004.
- He has worked at the Department of Materials Science throughout his career, first as a researcher from 1989 to 2004, as a senior researcher from 2005 to 2012 and as a professor from 2012 onwards.
- He currently holds the only professorship in Finland that is solely focused on ceramic materials.
- "At my age one already knows how to rejoice in the success of others, and teaching has become very close to my heart. The researchers in my group have a positive, can-do attitude."
- Levänen is a widely experienced scientist driven by endless curiosity: "A problem that keeps puzzling me is gradually transformed into a hypothesis followed by a frenzied period of working at the lab. Often the greatest feeling of accomplishment comes from developing a novel perspective on prior knowledge rather than discovering something entirely new."
At the interface of fundamental and applied research
Industrial collaboration continues to be the driving force behind the University's research excellence in the area. An important platform for further collaboration is FIMECC, the Finnish Metals and Engineering Competence Cluster Ltd.
"We pursue research under FIMECC's Breakthrough Materials theme and carry out projects that are funded by the Finnish Funding Agency for Technology and Innovation Tekes or commissioned by industrial clients. We're also continuously seeking to broaden and deepen our expertise by conducting fundamental research," says Levänen, summing up the activities of his group.
Professor Levänen's group has maintained its standing as one of the world's leading research units that explore ceramics used in combustion and gasification processes. The group's other key strengths include the mechanical properties and wear resistance of ceramics. This expertise is especially needed in the design of paper machines.
Space-age ceramics put to the test
Since ceramics undergo no chemical reactions or dissolve in the human body, they are ideal biomaterials that repair and regenerate living tissue. Oxide ceramics boast excellent wear resistance and are therefore used in hip joint implants. Porous ceramics can be used to bond the implant to the surrounding tissue.
Functionality is an added requirement that modern ceramics must meet.
"In this context, functionality refers to low friction, the ability to adjust to the environment, dirt and water resistance, and antibacterial properties. We already know how to integrate individual functionalities into ceramics, but there's still some way to go before multifunctional ceramics become a reality," says Levänen.
Researchers at Tampere University of Technology are currently developing functional ceramics in collaboration with Chinese partners. The joint project is sponsored by the Academy of Finland.
"We're making powders from ceramic raw materials by combining, among others, oxide nanoparticles, antibacterial substances and photocatalytic materials. The powders can be used as coatings or shaped into different objects," explains Levänen.
Another project funded by the EU aims to develop non-flammable ceramic insulation materials for the construction industry.