By combining the enhanced photosensitive properties of zinc oxide nanoparticles and the excellent transport characteristics of graphene, UV-sensitive, solar-blind hybrid optoelectronic devices have been demonstrated. These hybrid devices offer high responsivity and gain, making them well suited for photodetector applications. Here, we report a hybrid ZnO nanoparticle/graphene phototransistor that exhibits a responsivity up to 4 × 10⁴ AW⁻¹ and gain of up to 1.3 × 10⁵ with high UV wavelength selectivity. ZnO nanoparticles were synthesized by pulsed laser fragmentation in liquid to attain a simple, efficient, ligand-free method for nanoparticle fabrication. By combining simple fabrication processes with a promising device architecture, highly sensitive ZnO nanoparticle/graphene UV photodetectors were successfully demonstrated.

Electronic paper, or e-Paper, for use in displays has seen rapid growth in the past decade because of its potential as an alternative to traditional transmissive displays. Offering several critical advantages over current display technologies, including high contrast in direct sunlight, wide viewing angles, and compatibility with flexible substrate processing, electrowetting displays (EWDs) have made it to the forefront of e-Paper research and development efforts. Here, we describe a new design for the fabrication of multi-color, bistable electrowetting displays. Using a laser-based process to pattern an in-plane electrode design, liquid can be manipulated out-of-plane. This process relies on electromechanical pressure forcing water in and out of channels, causing colored oil to be displaced. When voltage is removed, the oil remains in its current position, resulting in bistability. We have demonstrated multi-color, bistable pixels that maintain their state at V = 0 for several days, which drastically reduces the power required to drive the display.

The combination of magnetostrictive thin films with surface acoustic wave (SAW) devices enables the magnetic sensors that exploit the Δ E-effect (magnetically induced change in modulus) without the need for free-standing structures that are susceptible to vibration and damage. The performance of these sensors is strongly influenced by magnetic anisotropy and, therefore, the state of stress in the magnetostrictive film. We report the fabrication and characterization of magnetic SAW devices comprised of a magnetostrictive layer and interdigital transducers on a piezoelectric substrate. The state of stress in the magnetostrictive layer is varied by annealing. Vibrating-sample magnetometer measurements indicate that the annealed devices show a strong uniaxial anisotropy with the easy axis parallel to the direction of acoustic propagation. The induced magnetic anisotropy is attributed to the anisotropic thermal expansion in the substrate. The change in frequency of one-port resonators and two-port SAW oscillators is measured as a function of dc bias field and ambient temperature. The normalized change in frequency (Δ f/fsat) is on the order of 10⁻⁴. These results demonstrate that the film stress can be used to optimize the performance of magnetic SAW devices and the SAW devices can be used to characterize the state of stress and magnetic anisotropy of magnetostrictive films.

Circular arrays offer the ability to form directional beams throughout a full 360 degrees of azimuth coverage without the drawbacks of beam broadening and/or scan loss. These advantages make them an attractive choice for a WiMAX base station antenna where the directional beams in any arbitrary direction facilitate range extension and throughput. In this paper, we demonstrate a 3D-printed circular array that provides a low cost design with simple manufacturing that is suitable for WiMAX base station operation from 5.1 -- 5.8 GHz.

A scalable laser lithographic process has been used to striate second-generation high-temperature superconducting coated conductors manufactured with a rolling-assisted biaxially textured substrate and metal organic deposition process by American Superconductor Corporation to reduce ac losses for electric power applications. The process involves laser patterning a resist coating and etching, which can be scaled up for commercial production. The results show that the critical current, $\boldsymbol{I}_{\boldsymbol{c}}$ , is not degraded for striation widths greater than 150 μm and that the ac losses for the 150-μm wide striations are reduced from the unpatterned 1-cm wide conductor by a factor of 15 for a 60-mT perpendicular peak magnetic field at 50 Hz.