Inhomogeneities in single crystals of cuprate oxide superconductors

The next stage in the evolution of experimental research on the high temperature superconductors will require high quality single crystals and epitaxially grown crystalline films. However, inhomogeneities and other defects are not uncommon in single crystals of cuprate oxide superconductors, so a corollary requirement will be a reliable method for judging the quality of these materials. The application of magnetically modulated resistance methods in this task is briefly described and illustrated

Influence of optical standing waves on the femtosecond laser-induced forward transfer of transparent thin films

The effects of the formation of an optical standing wave during femtosecond laser-induced forward transfer of transparent films is analyzed using a numerical interference model. The dependence of the intensity distribution on a number of easily controllable experimental parameters is investigated. Results of the model are compared to experimental studies of the transfer of gadolinium gallium oxide (GdGaO) with a polymer sacrificial layer. The model allows us to explain the observed variation in deposit morphology with the size of the air gap, and why forward transfer of the GdGaO was possible below the ablation thresholds of polymer and oxide

Fluxless flip-chip bonding of single photodetector chips using laser-induced forward transfer

We demonstrate the successful flip-chip bonding and DC characterization of commercial photodiode chips via micro-bumps of indium and silver nano-particle (AgNP) based inks, printed using the Laser-Induced Forward Transfer (LIFT) technique

Biofabrication: an overview of the approaches used for printing of living cells

The development of cell printing is vital for establishing biofabrication approaches as clinically relevant tools. Achieving this requires bio-inks which must not only be easily printable, but also allow controllable and reproducible printing of cells. This review outlines the general principles and current progress and compares the advantages and challenges for the most widely used biofabrication techniques for printing cells: extrusion, laser, microvalve, inkjet and tissue fragment printing. It is expected that significant advances in cell printing will result from synergistic combinations of these techniques and lead to optimised resolution, throughput and the overall complexity of printed constructs

Laser-induced forward transfer of focussed ion beam pre-machined donors

In this paper we report femtosecond laser-induced forward transfer (LIFT) of pre-machined donor films. 1 µm thick zinc oxide (ZnO) films were first machined using the focussed ion beam (FIB) technique up to a depth of 0.8 µm. Debris-free micro-pellets of ZnO with extremely smooth edges and surface uniformity were subsequently printed from these pre-machined donors using LIFT. Printing results of non-machined ZnO donor films and films deposited on top of a polymer dynamic release layer (DRL) are also presented for comparison, indicating the superior quality of transfer achievable and utility of this pre-machining technique

Micron-scale copper wires printed using femtosecond laser-induced forward transfer with automated donor replenishment

We demonstrate the use of laser-induced forward transfer (LIFT) in combination with a novel donor replenishment scheme to print continuous copper wires. Wires of mm length, a few microns wide and sub-micron in height have been printed using a 800 nm, 1 kHz repetition rate, 150 fs pulsed laser. A 120 nm thick copper donor was used along with laser pulse energy densities of 0.16-0.21 J cm-2 to print overlapping few-micron sized pads to form the millimeter long wires. The wires have a measured resistivity of 17 ± 4 times that of bulk copper