Search results for "Photoresist"

Fast and blister-free irradiation conditions for cross-linking of PMMA induced by 2MeV protons

2013

For soft lithography, the conventional negative tone resists, such as SU-8, that are used to create the mold have a number of drawbacks. PMMA, which is normally used as a positive tone resist, can be used as a negative resist by using high-fluence irradiation conditions. In this report, we outline optimization of the irradiation conditions for PMMA thin films using 2MeV H^+ ions to exploit their ability to work as a negative tone resist at ion fluences above 1.0x10^1^5ionscm^-^2. The main aim was to induce cross-linking while maintaining the exposed regions free of blisters and maintaining short irradiation times. We found that by using a two-step process with a low-flux irradiation, follow…

The photochemical rearrangement of polymeric N-(1-pyridinio) amidates. A novel, aqueous photoresist system

1988

Transfer of plasmid DNA into cells with microelectroporation arrays on a chip

2000

The possibility to transfer pure DNA into bacterial cells forms the basis for the genetic engineering of the cell. Electroporation is a powerful and easy technique to introduce plasmid DNA into cells. Its drawback for use with high-throughput approaches is that with standard electroporation chambers the reactions have to carried out one after the other and the electroporation cuvettes are expensive. To obtain the possibility of high-throughput electroporation reactions Escherichia coli cells were electroinjected in parallel with different plasmids in reactions as small as 100 nl on a microstructured array of electrodes, forming hundred separate electroporation units on a chip of a square in…

Towards metal chalcogenide nanowire-based colour-sensitive photodetectors

2018

Financial support provided by Scientific Research Project for Students and Young Researchers Nr. SJZ/2016/6 realized at the Institute of Solid State Physics, University of Latvia is greatly acknowledged. Authors are grateful to Reinis Ignatans for XRD measurements.

The measurement of light transmission through an irradiated fluidised bed

1983

Abstract The transmission of light through an irradiated fluidised bed with vertical flat walls containing catalytic particles has been experimentally studied. The amount of light transmitted through the reactor was measured at different levels by a photocell. The experimental variables studied included: (i) gas flow rate, varying from 2 to more than 10 times that required for minimum fluidisation; (ii) mean particle size, ranging from 0.138 to 0.275 mm; and (iii) internal bed thickness from 2.1 to 4.9 mm. The effect of the reflectance of the particles was also examined. Results show that the amount of light transmitted through a flat fluidised bed is low. The average transmitted light has …

Investigations of As-S-Se thin films for use as inorganic photoresist for digital image-matrix holography

2011

AbstractAs-S-Se chalcogenide thin films are successfully employed in classical and dot-matrix holography as inorganic photoresists for obtaining a relief-phase hologram. However using these films for image-matrix hologram recording has not been studied due to some features of image-matrix technology. For the applied research of the optical properties of As-S-Se films an experimental device of digital image-matrix holographic recording based on 100 mW 405 nm semi-conductor laser and Spatial Light Modulator (SLM) has been created. The device has the following main parameters: 140 × 105 µm frame size; laser intensity during exposure 10 W/cm2. With the help of this device diffraction grating an…

Photoinduced mass transport in low molecular organic glasses and its practical application in holography

2015

Abstract In this paper we present the synthesis and optical properties of amorphous low molecular compound 4-((4-(bis(5,5,5-Triphenylpentyl)amino)phenyl)diazenyl)benzoic acid. The surface relief gratings formation by polarization holography method on these thin films (thicknesses are 200–1700 nm) was shown. The dependence of the surface relief modulation on various parameters: recording exposure dose, the polarization state of the recording beams, the grating period and the film thickness of the material was demonstrated. Values of surface tension at the air-film before and after irradiation of the substance by polarized radiation were measured. The efficiency of surface relief formation in…

Infrared microspectroscopy of biochemical response of living cells in microfabricated devices

2010

Abstract First experiments demonstrating the suitability of novel microfabricated fluidic devices for measuring living cells in physiological environment by synchrotron radiation (SR) Fourier Transform Infrared microspectroscopy (μ-FTIR) are presented. The devices were fabricated on CaF 2 windows, using the photoresist XARP 3100/10 to define the liquid cell lay-out. Therefore, the sample holder is transparent to both visible and infrared light, robust, completely recyclable and with a precise spacing. Using prototype devices of thicknesses 9, 5 and 3 μm, we studied the response of the U937 monocytic cell line to mechanical compression. The temporal evolution of the FTIR spectra, characteris…

Surface Periodic Poling in Lithium Niobate and Lithium Tantalate

2005

Periodic Poling of Lithium Niobate crystals (PPLN) by means of electric field has revealed the best technique for finely tailoring PPLN structures and parameters, which play a central role in many current researches in the field of nonlinear integrated optics. Besides the most studied technique of bulk poling, recently a novel technique where domain inversion occurs just in a surface layer using photoresist or silica masks has been devised and studied. This surface periodic poling (SPP) approach is best suited when light is confined in a thin surface guiding layer or stripe, as in the case of optical waveguide devices. Also, we found that SPP respect to bulk poling offers two orders of magn…

MWP true time delay implemented in PbS-SU8 waveguides

2015

Es presenta un nou tipus de dispositiu de retard en temps real de microones (TTD) basat en la dispersió de punts quàntics col·loïdals PbS (QD) en el fotoresist SU8 disponible comercialment. Amb aquest propòsit, els nanocompostos PbS-SU8 s’integren en una plataforma de silici en forma de guies d’ones de cresta. Quan aquestes estructures es bomben a longituds d’ona per sota de l’interval de banda dels PbS QD, es realitza un desplaçament de fase en un senyal de microones transmès òpticament (a 1550 nm) i, per tant, es produeix un retard temporal. A més, es milloren els resultats mitjançant la implementació d’una nova guia d’ones de doble capa de cresta composta per un nanocompost PbS-SU8 i una…