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
Neutron star merger directly observed for the first time
17.10.2017 | University of Maryland
Breaking: the first light from two neutron stars merging
17.10.2017 | American Association for the Advancement of Science
University of Maryland researchers contribute to historic detection of gravitational waves and light created by event
On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
17.10.2017 | Event News
10.10.2017 | Event News
10.10.2017 | Event News
17.10.2017 | Life Sciences
17.10.2017 | Life Sciences
17.10.2017 | Earth Sciences