VUFF

The group’s main research topic is direct laser writing (DLW) of 3D micro-nano-structures in transparent media and the applications of such functional structures in microoptics, photonics and tissue engineering. The group started its activity in 2004, developing a new and very perspective technology for the fabrication of 3D polymeric microstructures by utilizing a two-photon polymerization reaction initiated in the focal spot of a focused laser beam. In 2006-2008, in collaboration with the company Altechna a universal automated experimental system for DLW was created and developed, which allows fabrication of polymeric structures in wide area (1-10 cm) with very high resolution (100 nm and lower). By the use of ultra-short laser pulses, this technology makes it possible to fabricate functional structures out of a vast variety of photosensitive materials, such as acrylates, epoxies, hybrid organic-inorganic materials and biopolymers. DLW technology is also used for the fabrication of complex 3D photonic structures in transparent solids by a permanent local modification of their refractive index. Such photonic crystals are used to control the propagation of light in micrometer scale. In 2008, the group started employing a soft lithography replication technique for the rapid production of identical copies of the 2.5D structures. A mold of such a structure is created using a laser-structured object and later used to make identical copies of the original object out of various materials, including thermopolymers or polymers with special additives.

The group is actively participating in interdisciplinary research. In collaboration with researchers from the Institute of Biochemistry (Dr. V. Bukelskienė and Dr. D. Baltriukienė) and Heart Surgery Center (Prof. V. Sirvydis and Dr. A Širmenis) the technologies developed in the LRC are being applied to fabricate scaffolds out of biocompatible polymers for the growth of stem cells in pursuit of creating artificial biotissues for heart and blood-vessel surgery. In addition, 3D scaffolds for the treatment of bone defects are being fabricated using thermal extrusion printing out of bioresorbable polymers in collaboration with the VU Faculty of Medicine Institute of Odontology (Dr. V. Rutkūnas). Joint work with the Proteomics Center (Dr. M. Valius) resulted in the fabrication of variable period scaffolds out of biocompatible polymers, as well as precise decoration of scaffolds with bioactive molecules.

Recently, it has been shown that DLW technology is promising for the fabrication of multifunctional and integrated microoptical components (project “MikroŠviesa” executed in collaboration with Dr. E. Brasselet from the University of Bordeaux and funded by the Research Council of Lithuania) as well as various functional components for lab-on-a-chip applications. DLW in polymers and glasses might also be used for the creation and manufacturing of 3D photonic crystals. In collaboration with Prof. K. Staliūnas’ group (Polytechnic University of Catalonia, Barcelona, Spain) an array of applications of such nanostructures for the control of the chromatic and spatial properties of light at microscale level has been demonstrated.

In spite of the fact that the DLW technology has been developed worldwide for over a decade, some of the mechanisms of light and polymer interaction under tight focusing conditions are still an object for discussion. This is being actively investigated in collaboration with Prof. S. Juodkazis (Swinburne University of Technology, Melbourne, Australia) and Dr. M. Farsari (Foundation for Research and Technology-Hellas, Heraklion, Greece). A significant review of this topic has been published in the journal Physics Reports.

In 2013, Prof. R. Gadonas and PhD student V. Purlys, along with Šviesos konversija and other investors, applied the group’s experience commercially by forming a spin-off high-tech company Femtika. At this time, the company is working on a project funded by the Lithuanian Business Support Agency (LBSA), is actively developing the technologies of direct laser writing, perfects the hardware as well as offering research and experimental development services to other high-tech companies and science institutions.

LzNanoFot grNanophotonics group in the laboratory. Seated from the left: PhD stud. A. Žukauskas, PhD stud. S. Rekštytė, stud. A. Galvelytė; standing from the left: MSc stud. D. Gailevičius, Dr. M. Malinauskas, Prof. A.P. Piskarskas, Dr. V. Purlys, MSc stud. T. Jonavičius and Prof. R. Gadonas

LzNanoFot pvzExamples of functional three-dimensional microstructures: a hybrid optical element on the fiber tip (a), a flexible chain-mail type scaffold (b) and a polymeric photonic crystal (c)

 

Group members:

  • Prof. R. Gadonas,
  • Prof. A.P. Piskarskas,
  • Dr. M. Malinauskas,
  • Dr. V. Purlys,
  • Dr. S. Rekštytė,
  • PhD students D. Gailevičius, T. Tičkūnas, L. Jonušauskas and S. Varapnickas,
  • Engineer A. Čiburys,
  • Masters students L. Čekanavičius, G. Kontenis, S. Vaisiūnas, A. Butkutė, G. Grigalevičiūtė, G. Nemickas and E. Skliutas,
  • Bachelor students R. Pakalnytė and V. Podolskytė.

Main research topics:

  • The development of multifunctional and integrated microoptical components for manipulation of the propagation of light;
  • Fabrication of 3D microporous scaffolds for biomedical applications out of biocompatible and biodegradable materials;
  • Development and investigation of photonic crystals for manipulation of the spectral and spatial characteristics of light;
  • Investigation of the light-material interaction at fabrication conditions;
  • Development of other additive fabrication and replication technologies for applications in biomedicine, photonics and microfluidics.

The research is carried out in collaboration with foreign science institutions: Swinburne University of Technology (Melbourne, Australia), Foundation for Research and Technology-Hellas (Heraklion, Greece), Laser Zentrum Hannover (Hannover, Germany), Polytechnic University of Catalonia (Barcelona, Spain) and University of Bordeaux (Bordeaux, France). The group has published 3 book chapters and more than 100 scientific articles, which have been cited over 1000 times in total.

The research activities are summarized in a topical review: Light: Science & Applications (2016) 5, e16133; doi:10.1038/lsa.2016.133

Laboratory equipment:

  • fs lasers with tunable repetition rate and wavelength;
  • Precision XYZ positioning stages with beam deflection system;
  • Chemistry laboratory with universal equipment for preparation of polymer samples;
  • Scanning electron microscope;
  • Fused filament fabrication 3D printer.

LzNanoFot schemaLaser nanophotonic lithography system for the fabrication of 3D structures