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Silver, gold, and copper nanoparticles are an excellent platform for the manifold of applications not limited to sensing, biomedicine, and nanophotonics [1]. These metal nanostructures demonstrate the remarkable size and shape-determined optical properties related to localized surface plasmon resonance (LSPR) which appears as strong light scattering and/or absorption bands. Dense random ensembles of Ag and Au nanoparticles increase the light fields and are beneficial for surface-enhanced Raman spectroscopy (SERS). Light scattered by the subwavelength period regular arrays of nanoparticles on the surfaces can interact resonantly narrowing down the LSPR peaks into high-quality factor surface lattice resonances (SLR). Such structures are called metasurfaces and find numerous applications in optics and nanophotonics [2]. Different nanomaterial synthesis approaches are developed enabling control of the size, shape, structure, and surface quality of the nanomaterials [3,4]. In this work, silver, gold, and copper nanoparticle colloids were synthesized employing chemical or photophysical synthesis methods seeking applications in metasurface-based SERS substrates, lateral flow assays, and of antiviral surfaces. Nanoparticle colloids were chemically synthesized using the seed growth method or femtosecond laser ablated from pure metal targets employing Yb:KGW femtosecond laser Pharos (Light Conversion). The nanoparticle sizes were inspected with the field emission scanning electron microscope and transmission electron microscopes (FEI). Monodisperse nanoparticles were deposited into polymer replica templates using the capillarity-assisted particle assembly (CAPA) method. The optical density of the colloids and nanoparticle arrays were evaluated with the steady state (Avantes) and transient absorption (Light Conversion) spectrometers. Field enhancement of nanoparticle assemblies was investigated by a Raman spectrometer (Renishaw). Strongly absorbing silver, gold, and copper colloids of yellow, dark green, and pink color were synthesized. Multi-wavelength Raman measurements of SERS substrates with 532 nm matched SLR peak indicated strong signal enhancement for detection of the 2NT analyte molecule. In cooperation with UAB “Imunodiagnostika” the antibody functionalized gold nanoparticles were successfully used to detect SARS-CoV-2 nucleoprotein in lateral flow assay tests. Aerograph spray deposited copper nanoparticles on glass substrates demonstrated antiviral efficacy against BHV-1 and IBV.

Chemically synthesized silver nanoparticles of different average sizes (70 nm - 130 nm) were deposited into regular lattices on PDMS templates by the CAPA method. The fabricated arrays exhibited SLR. The effect of the nanoparticle size on the SLR peak position and the SERS activity related to the excitation wavelength and SLR peak position overlap was investigated. The overlapping positions at 532 nm excitation wavelength, the enhancement factor reached 108, and the detection limit for 2-naphthalenethiol molecules - 10-8 M.

Chemical vapor deposited nitrogen-doped graphene, transferred on SiO2/Si substrate was selectively patterned by femtosecond laser ablation for formation of the topology dedicated for charge carrier measurements. Ultrashort 1030 nm wavelength Yb:KGW fs-laser pulses of 22 μJ energy,14 mJ/cm2 fluence, 96% pulse overlap and scanning speed of 100 mm/s were found to be optimum regime for the high throughput microstructure ablation in graphene, without surface damage of the substrate in the employed fs-laser micromachining workstation. Optical scanning electron, atomic force microscopy as well as Raman spectroscopy were applied to clarify the intensive fs-laser light irradiation effects on graphene and substrate as well as to verify the quality of the graphene removal. Measurements of magnetotransport properties of the fs-laser ablated nitrogen-doped graphene microstructure in the Hall configuration enabled determination of the type as well as concentration of charge carriers in a wide temperature range.

In this paper we describe fabrication and characterization methods of two-dimensional periodic microstructures in photoresist with pitch of 1.2 urn and lattice constant 1.2-4.8 μm, formed using two-beam multiple exposure holographic lithography technique. The regular structures were recorded employing different angular positions of the sample in between two and three sequential exposures, adding up fringes of various symmetries on thin positive tone photoresist layer spin-coated on floated glass substrates. After exposure and development, the resulting structures were analysed employing optical and scanning electron microscopy. It was demonstrated that structures with rhombus, triangular and square point lattice types with 2-fold, 4-fold or 6-fold rotational symmetry can be obtained. The results obtained from the micrographs were compared with the simulation results of interference field light intensity distribution. Camera images of the transmitted and diffracted laser beam light far field spatial distribution were compared with the fast Fourier transforms (FFT) of optical microscope dark field micrographs. Diffraction efficiency measurements were demonstrated as an efficient method to control quality of the structures as well as to optimize the multiple exposure processes.

The objective of the research was to explore potential application of diamond-like carbon (DLC) nanofilms for nanodosimetry of ionizing radiation (IR) by studying the changes of photoelectron emission (PE) from the nanofilms under influence of ultraviolet (UV) radiation. The results show that increment of charge released by photoelectrons from DLC nanofilms correlates to time of UV exposure. Metal doped and non-doped DLC nanofilms react differently to the UV irradiation.

Ionizing radiation affects the living cells at nanoscale; therefore, modern radiation therapy needs dose detection in nanovolumes [1]. It would be possible to apply the nanodosimeters in radiobiology in order to obtain measurements that could enhance the knowledge of how ionizing radiation affects the DNA and other cell structures. This knowledge could improve effectiveness of radiation therapy. Currently nanoscaled dosimeters do not exist. In order to measure the dose of ionizing radiation absorbed by nanovolumes, at least the thickness of the dosimeter should be nanosized [1]. Solid material that can be used for the nanodosimeter should have properties of either semiconductor or dielectric to store the electric charge induced by radiation for a long time. Diamond-like carbon (DLC) belongs to such material and could be fabricated as the nanofilm. The DLC nanofilms were fabricated by ion deposition technology. The specimens were synthesized using HMDSO+H2 and C2H2 gases and had thickness of 200 nm. Some specimens were doped with Cu and Ag and had thickness of 100 nm. The readout of the absorbed dose was provided by the photoelectron emission measured from the specimens. The specimens were radiated with ultraviolet (Xe+Hg tube) at 5, 10, 15 and 20 minutes of exposures. The ultraviolet radiation (UV) was selected as a model for testing the potential ability of the photoelectron emission to provide the dose readout. The increment of photoelectrons released charge (relative to non-radiated specimens) correlated to the UV exposure.

Aim of the study was to assess effectiveness of cold – heat contrast and local compression therapy device in physiotherapy for the patients with latent myofascial trigger points effects. Device (patent number A61F 7/00) originally constructed in Kaunas University of Technology, Institute of Physical Electronics used in this research consists of a controller and thermoelectric module with integrated force measurement module. 37 computer users with pain and discomfort symptoms in the muscles of neck and shoulder area were recruited for this research. Used stretching exercises and cold-heat contrast and local compression therapy reduced pain in the muscles of neck and shoulder area (p, Eksperimento tikslas – įvertinti šaldymo bei šildymo ir lokaliosios kompresijos prietaiso efektyvumą fizioterapijoje, kai pacientams yra diagnozuoti latentiniai trigeriniai taškai. Buvo ištirti 37 darbingo amžiaus žmonės, dirbantys kompiuteriu ir jaučiantys skausmą ar diskomfortą kaklo bei pečių srityje. Po ištyrimo jie suskirstyti į tris grupes: 1) 15 tiriamųjų 6 savaites buvo taikyti tempimo pratimai, skirti kaklo bei peties srities raumenims. Tiriamieji pratimus atliko savarankiškai, prieš tai išėję mokymus bei gavę specialų lankstinuką; 2) 12 tiriamųjų buvo taikyta šaldymo ir šildymo terapija, skirta miofascijiniams trigeriniams taškams gydyti, naudojant originalų KTU Fizikinės elektronikos instituto sukurtą šaldymo ir šildymo įrenginį; 3) 10 tiriamųjų sudarė kontrolinę grupę ir jiems rekomendacijos bei tempimo pratimai buvo pateikti tyrimo pabaigoje (po 6 savaičių). Įvertinus taikytų gydymo priemonių efektyvumą nustatyta, kad didžiausią įtaką kaklo ir peties srities raumenims bei jaučiamam skausmui ar diskomfortui turėjo šaldymo ir šildymo ir lokaliosios kompresijos terapija, naudojant KTU FEI sukonstruotą prietaisą.

Aim of the study was to assess effectiveness of cold – heat contrast and local compression therapy device in physiotherapy for the patients with latent myofascial trigger points effects. Device (patent number A61F 7/00) originally constructed in Kaunas University of Technology, Institute of Physical Electronics used in this research consists of a controller and thermoelectric module with integrated force measurement module. 37 computer users with pain and discomfort symptoms in the muscles of neck and shoulder area were recruited for this research. Used stretching exercises and cold-heat contrast and local compression therapy reduced pain in the muscles of neck and shoulder area (p

Įrenginys suprojektuotas mikroprocesoriaus ir Peltje efekto termoelektrinio modulio pagrindu. Aprašytas veikimo principas. Įrenginys gali veikti cikliškai, atskirai nustatant šaldymo ir šildymo laiko trukmę, arba tik šaldymo, arba tik šildymo režimu. Pateiktas šilumos srauto į raumenį matavimo metodas, paremtas Furjė šilumos laidumo dėsniu. Atlikti eksperimentai, šaldant ir šildant žmogaus skirtingų dydžių raumenis – gastrocnemius caput mediale, aductor pollicis, biceps femoris. Rezultatai pateikti grafikuose ir apskaičiuota skirtingų raumenų grupių šilumos sugėrimo sparta., The unit is made on base of microprocessor and Peltier effect thermoelectric module. There is presented the principle of operation of unit. The unit is designed to work in continuous hot or cold, or cycle with predetermined time for cold and hot. In this paper the method of determining of heat flux into the muscle by law of Fourier is presented. The experiments had been performed on muscles of different size – gastrocnemius caput mediale, aductor pollicis, biceps femoris. The results are presented in graphic form. There are presented calculation of heat flux into the muscle.