Laser Therapy

Advances in existing and possibilities for novel laser therapies (primarily in dermatology, aesthetic surgery and stomatology) are investigated in numerical, in vitro, and clinical studies.
In collaboration with company Fotona (Ljubljana), Clinical Center Ljubljana, and Beckman Laser Institute and Medical Clinic, University of California at Irvine.

Biomedical Engineering

We investigate dynamic cooling with millisecond sprays of cryogenic liquid for application in dermatologic laser therapy. We participated in development of a cell culture model of human skin and its application in testing of novel laser therapies.
In collaboration with Beckman Laser Institute and Medical Clinic, University of California at Irvine.

E-beam litography

This is a standard procedure of nanoscopic circuit manufacture, very similar to fotolithography. Electron beam in a scanning electron microscope is used to chemicaly change polimer resist spun on a oxidized silicone wafer, resulting different solvabiliy of iluminated parts in a specific solvent. Drawn pattern emerges in a form of channels exposing the silicon substrate under the resist, so that afterwards sputtered metal attaches selectivelly on the surface of the resist and on the substrate. After the lift-off of the resist together with the metal on it, only structures on the subtrate remain, forming the drawn circuit. This techinque alows us to manfacture electrodes and devices as small as 300 nm so that we can use them in a variety of nanoscopic experiments that include small buildingblocks such as gold clusters, nanowires DNA, proteins etc. more

Electron beam writing substrate covered with a sensitive polymer paste is exposed to the electron beam moving in desired patterns.

Developing exposed areas of the polymer are more soluble in solvents and after etching those parts remain as a channels in the polymer layer.

Metal coating metal particles are sputtered onto the sample, but they are attached directly to the substrate only in channels.

Lift-off by using more aggressive solvent the rest of the polymer is etched off the substrate, while the metal layer remains on the substrate in desired patterns.

Some advantages of e-beam lithography over photolitography are:

- electron optics allows for better quality of the writing beam;

- electron writer can also be used as a regular scanning electron microscope;

- the smallest features are bellow 100nm in size, which presents the limit for photolitography.

Scaning electron microscope image of a cross section of a polymer paste after developing.

Atomic force microscope image of a 300 nm wide channel between two electodes.

Scanning electron microscope image of a transistor constructed by using e-beam lithography.