The new process is based on the use of visible light, ultra short pulse laser. When focused inside photopolymerizable material the radiation causes a reaction, where two photons are absorbed simultaneously, thus leading to the polymerization of the material. One of the advantages of this so called two-photon polymerization process is that the fabrication occurs below the surface of liquid material, and the polymerization is confined only to the point of focus whose diameter can be much less than 1 micrometer. The conventional ultraviolet light induced polymerization causes hardening of the material along the entire path of the UV-beam, thus making it impossible to form very small three dimensional features. The two photon polymerization process requires no utilization of special photolithographic masks since the structure is formed directly inside the liquid volume.
High accuracy biomaterial structures need to be used as tissue engineering scaffolds or cell culture platforms where the fine features have to follow the dimensions of the cultured cells. So far the smallest features achieved in this project have been about 700 nanometers wide. As a reference one can compare it to the epithelial cells, which have a diameter of 11000 - 12000 nm or viruses that range in size between 10 - 100 nm. The fabricated structures can be made of biodegradable materials and thus are biocompatible. The process can also be utilized in manufacturing structures for other applications, e.g. optical waveguides, photonic crystals, and microfluidic channels.
Another advantage of this process is the possibility to utilize an inexpensive, low-power laser. Other research groups have typically used very expensive femtosecond titanium-sapphire pulse lasers. A much cheaper laser that produces longer, picoseconds width pulses has been used in the project. As far as is known there is only one research group in the USA, that has previously succeeded in polymerizing biomaterials with a similar system.
The project has been accomplished as an interdisciplinary collaboration. Research Scientist Sanna Peltola from the Institute of Biomaterials, Tampere University of Technology has been responsible of the development of materials, and the research group of Research Professor Jouko Viitanen from VTT has developed the laser system. The stem cell culturing requirements have been specified by the researchers of the Tampere University. Nanofoot Finland Oy is commercializing the new process. The company offers versatile services in the area of laser machining.
Press Office | alfa
Climate cycles may explain how running water carved Mars' surface features
02.12.2016 | Penn State
What do Netflix, Google and planetary systems have in common?
02.12.2016 | University of Toronto
A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.
Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...
In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.
“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...
The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.
The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...
Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water
In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...
The efficiency of power electronic systems is not solely dependent on electrical efficiency but also on weight, for example, in mobile systems. When the weight of relevant components and devices in airplanes, for instance, is reduced, fuel savings can be achieved and correspondingly greenhouse gas emissions decreased. New materials and components based on gallium nitride (GaN) can help to reduce weight and increase the efficiency. With these new materials, power electronic switches can be operated at higher switching frequency, resulting in higher power density and lower material costs.
Researchers at the Fraunhofer Institute for Solar Energy Systems ISE together with partners have investigated how these materials can be used to make power...
16.11.2016 | Event News
01.11.2016 | Event News
14.10.2016 | Event News
02.12.2016 | Medical Engineering
02.12.2016 | Agricultural and Forestry Science
02.12.2016 | Physics and Astronomy