Constantly increasing demand of renewable and nonpolluting energy production methods has made solar cells one of today's hottest research areas. Developing more cost-effective fabrication methods that enable production of extremely non-refl ecting surfaces is one of the key issues in solar cell research. [ 1 , 2 ] Many other applications, such as miniaturized chemical analysis systems, would also benefi t greatly from low-cost surfaces with low and uniform refl ectivity. [ 3 ] Typically, suppression of Fresnel refl ection has been achieved by antirefl ective coatings, but they suppress refl ection effi ciently only in a narrow wavelength range. Suppression of refl ection over a broad spectral range can be achieved by using nanotextured surfaces that form a graded transition of the refractive index from air to the substrate. [ 1 , 2 , 4-12 ] Here, we present a scalable, high-throughput fabrication method for such non-refl ecting nanostructured surfaces. Original nanostructures are etched on a silicon wafer and replication methods enable their transfer into polymeric materials. Previously, transfer of non-refl ecting structures into polymeric materials has not received enough attention. The fabrication starts with a maskless plasma-etching step, which forms nanosized spikes on a silicon substrate. Using the Taguchi method, [ 13 ] we show that the sidewall angles and heights of the nanospikes are controlled by the plasma-etching parameters. A silicon surface with pyramidshaped nanospikes serves as a template in the fabrication of an elastomeric stamp, which enables replication of the original nanospike pattern into polymeric materials. Denser nanospike arrays with steeper sidewalls suppress the refl ection of light most effi ciently, but they are not well-suited for replication. The refl ection measurements show that all implemented nanostructured surfaces greatly reduce the refl ection of light over a broad spectrum and that the size of the nanospikes contributes substantially to the antirefl ection properties. Our application for non-refl ecting surfaces is laser desorption ionization mass spectrometry (LDI-MS), which is a common technique in chemical analysis. [ 3 , 14 ] As a consequence of suppressed light refl ection, lower laser fl uence is enough to desorb and ionize the analytes from a nanostructured surface. We also make the surfaces self-cleaning by coating them with a low surface energy fl uoropolymer. High-throughput fabrication of low-cost self-cleaning surfaces, which suppress the refl ection of light over a wide spectral range, is expected to have applications ranging from chemical analysis of drugs and biomolecules to photovoltaics.

Oleophobic surfaces capable of power-free self-transportation of oil droplets are designed.

Flexible electronics serve as the ubiquitous platform for the next-generation life science, environmental monitoring, display, and energy conversion applications. Outstanding multifunctional mechanical, thermal, electrical, and chemical properties of graphene combined with transparency and flexibility solidifies it as ideal for these applications. Although chemical vapor deposition (CVD) enables cost-effective fabrication of high-quality large-area graphene films, one critical bottleneck is an efficient and reproducible transfer of graphene to flexible substrates. We explore and describe a direct transfer method of 6-inch monolayer CVD graphene onto transparent and flexible substrate based on direct vapor phase deposition of conformal parylene on as-grown graphene/copper (Cu) film. The method is straightforward, scalable, cost-effective and reproducible. The transferred film showed high uniformity, lack of mechanical defects and sheet resistance for doped graphene as low as 18 Ω/sq and 96.5% transparency at 550 nm while withstanding high strain. To underline that the introduced technique is capable of delivering graphene films for next-generation flexible applications we demonstrate a wearable capacitive controller, a heater, and a self-powered triboelectric sensor. PAPER Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence.

. 2012. Surface-tension driven self-assembly of microchips on hydrophobic receptor sites with water using forced wetting.