The deposition of nanoliter and subnanoliter volumes is important in chemical and biochemical droplet-based microfluidic systems. There are several techniques that have been established for the deposition/generation of small volumes including the use of surfaces with patterned differences in wettability. Many such methods require complex and time-consuming lithographic techniques. Here, we present a facile method for the fabrication of superhydrophobic surfaces with patterned hydrophilic regions by laser micromachining. A comprehensive study of fabrication parameters (laser machining speed, laser power, and patch size) on the material, patch wettability, and droplet volume is presented. Patch sizes as small as 100 μm diameter and as large as 1500 μm diameter were investigated, and volumes as low as 400 pL were observed. As an example application of such patterned materials and the deposition of small volumes, halide salts were preconcentrated on the hydrophilic patches, and their fluorescence quenching constants were rapidly calculated using a 3D-printed device coupled to a fluorescence spectrometer.

This paper reports on the performance and environmental endurance of the recently presented wirelessly communicating smart textiles with integrated multi-material fiber antennas. Metal–glass–polymer fiber composites were fabricated using sub-1 mm hollow-core silica fibers and liquid state silver deposition technique. These fibers were then integrated into textiles in the form of center-fed dipole and loop antennas during standard weaving procedure. Fiber antennas performance was found to be directly comparable to classic ‘rigid’ solutions in terms of return loss, gain and radiation patterns, which allowed transmitting data through Bluetooth protocol at 2.4 GHz frequency. Applied superhydrophobic coatings (water contact angle = 152°, sliding angle = 6°) allow uninterrupted wireless communication of the textiles under direct water application even after multiple washing cycles.

This work highlights the possibility of using microstructured fibres with predefined doped regions to produce functional microstructures at a fibre facet with differential chemical etching. A specially designed silica microstructured fibre (MSF) that possesses specific boron-doped silica regions was fabricated for the purpose of generating a radial micronozzle array. The MSF was drawn from a preform comprising pure silica capillaries surrounded by boron-doped silica rods. Different etching rates of the boron-doped and silica regions at the fiber facet produces raised nozzles where the silica capillaries were placed. Fabrication parameters were explored in relation to the fidelity and protrusion length of the nozzle. Using etching alone, the nozzle protrusion length was limited, and the inner diameter of the channels in the array is expanded. However with the addition of a protective water counter flow, nozzle protrusion is increased to 60 μm with a limited increase in hole diameter. The radial micronozzle array generated nine individual electrosprays which were characterized using spray current measurements and related to theoretical prediction. Signal enhancement for the higher charge state ions for two peptides showed a substantial signal enhancement compared to conventional emitter technology.

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Precision glass tubes for analytical instrumentation often require tight tolerances in their inner and outer diameter, which makes them cumbersome to fabricate. The extrusion method is a potential method for the fabrication of precision glass tubes, however, the effects of die swell and taper which occur during the extrusion process can distort the final product. This work aims to determine the tolerances that can be achieved for glass tubes fabricated using the extrusion method by comparing the extent of the die swell and tapering on tubes extruded under a variety of extrusion parameters. Lead‐silicate glass tubes of 6.5 mm outer diameter and 0.50 mm inner diameter were fabricated with a taper of <1% for the outer diameter and <5% for the inner diameter over 200 mm lengths. This target geometry was achieved using a volume flow rate of 4.7 mm3/s, a glass viscosity of 107.2 Pa.s and a die geometry that accommodated a 8%‐10% offset due to die swell. This result indicates the extrusion method is a viable method for producing glass tubes with tight tolerances for applications in analytical instrumentation.