Papers by Keyword: Piranha Solution

Abstract: In our work, we aimed to improve the interfacial properties of the Polyetheretherketone (PEEK) polymer/carbon fiber (CF) by treating the fibers with wet chemical method, a higly oxidative chemical solutions called piranha solution and chromate solution. The changes of the surface funtional groups, chemical compositions and structures of the carbon fibers were characterized by X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR),surface morphology was studied by scanning electron microscopy (SEM), mechanical interfacial properties of the composites was evaluated by means of interlaminar shear strength (ILSS) tests. The results indicated that graphitic carbon was the major carbon functional component on the carbon fiber surfaces and other functional groups were also presented, such as C–O, C-OH, C = O. Consequently, these introductions of oxygen functional groups onto the carbon fiber surfaces led to an improvement of the ILSS of the composites.

Abstract: This paper describes a new fabrication technique for RF MEMS switches where the coplanar waveguide (CPW) is fabricated in a basin. A planar profile and good coverage at the edges in a basin is achieved by spinning and baking the sacrificial positive photoresist (PPR) in multiple steps to fill the basin. The basin structure allows an increase in the length of the membrane resulting in lower pull-in voltage and better isolation. The PPR is removed using Piranha solution (H2SO4:H2O2::3:1). Structures with the gap of about 2.5 µm and the thickness of the gold membrane varying from 1µm to 2.5 µm have been successfully realized.