Biomimetic surface imitating microstructure of a lotus leaf cuticle was reproduced synthetically in industrial-grade silicone rubber specimens by means of direct replica method using random templates. The specimens displayed roughness-induced increase of water contact angle and were characterized by static contact angle at 150° superhydrophobic limit. Biomimetic silicone rubber specimens were also tested for prolonged exposure to air corona discharges. Resultant loss of superhydrophobicity was accredited to elimination of microstructural features necessary for roughnessinduced hydrophobicity boost due to physical etching of rough surface by coronagenerated charged ion bombardment.

Ozone, due to its high reactivity cannot be stockpiled, and thus requires to be generated on-demand. The paper reports on laboratory studies of O₃ generation in a volume dielectric barrier discharge (DBD) tubular flow-through system with a coaxial-spiral electrode arrangement. Its performance is experimentally verified and compared to a commercial surface DBD O₃ source fitted with a three-electrode floating supply arrangement. The presented volume DBD design is capable of steadily producing up to 4180 ppm_v O₃ at 1 Nl/min unprocessed atmospheric air intake and 10 kV 1.6 kHz sinusoidal high voltage supply corresponding to 67 g/kWh O₃ production yield increasing to 93 g/kWh at 100 Nl/min air intake. The effects of high voltage supply tuning are also investigated and discussed together with finite element method simulation results.

The paper presents a minimal approach to produce superhydrophobic, surface-conducting silicone rubber with a strongly developed surface modified with multiwall carbon nanotubes partially embedded in the silicone elastic matrix. The modification was achieved by physical deposition of carbon nanotube powder on a semi-liquid silicone rubber surface prior to its cross-linking. The resulting biomimetic material displayed superhydrophobic properties (static wetting angle >160°, sliding angle ∼10°), as well as elevated electric surface resistance (surface resistivity approx 18 k Ω ). A piezoresistive hysteretic response with nonmonotonic change of the surface resistance accompanying substantial linear stretching was also demonstrated in the developed specimens displaying negative resistance change in a broad range of extension ratios, making them applicable as highly compliant, large-specific-area electrodes.

This paper presents construction and performance of a novel hybrid microelectromechanical system (MEMS) vortex flowmeter. A miniature cantilever MEMS displacement sensor was used to detect frequency of vortices development. 3-mm-long silicon cantilever, protruding directly out of a trailing edge of a trapezoidal glass-epoxy composite bluff body was put into oscillatory motion by vortices shed alternately from side surfaces of the obstacle. Verified linear measurement range of the device extended from 5 to 22 m/s; however, it could be broadened in absence of external 50-Hz mains electrical interfering signal which required bandpass frequency-domain digital sensor signal processing. The MEMS vortex sensor proved its effectiveness in detection of semilaminar airflow velocity distribution in a 40-mm-diameter tubular pipe.