Graphene nanoplatelets (GNPs) are novel nanofillers possessing attractive characteristics, including robust compatibility with most polymers, high absolute strength, and cost effectiveness. In this study, GNPs were used to reinforce epoxy composite and epoxy/carbon fiber composite laminates to enhance their mechanical properties. The mechanical properties of GNPs/epoxy nanocomposite, such as ultimate tensile strength and flexure properties, were investigated. The fatigue life of epoxy/carbon fiber composite laminate with GPs-added 0.25 wt% was increased over that of neat laminates at all levels of cyclic stress. Consequently, significant improvement in the mechanical properties of ultimate tensile strength, flexure, and fatigue life was attained for these epoxy resin composites and carbon fiber-reinforced epoxy composite laminates.

An extreme high fill-factor microlens array mold insert in photoresist fabrication using a thermal reflow process is presented. The experimental results proved that a square microlens array could be produced without a peripheral gap. A square microlens array with an extreme high fill-factor (almost 100%) was successfully fabricated. In this experiment, square photoresist columns were formed on a silicon substrate using a lithographic process. The square pattern was laid out in an ortho-square on a polyethylene terephthalate (PET) based mask. Precise temperature and time control was used during the thermal reflow process. The square microlens array was formed from the uniformly flowing melted photoresist. The photoresist column surface transforms into a spherical profile due to the surface tension effect. The error was within ±8% between the fabricated microlens characteristics and the theoretical model used to predict the photoresist column thickness and actual thickness. This model is feasible for fabricating various sized high fill-factor square microlens arrays.

In this paper we present a silicon wafer bonding technique for 3D microstructures using MEMS process technology. Photo-definable material with patternable characteristics served as the bonding layer between the silicon wafers. A bonding process was developed and several types of photo-definable material were tested for bonding strength and pattern spatial resolution. The results indicated that SU-8 is the best material with a bonding strength of up to 213 kg cm−2 (20.6 MPa), and a spatial resolution of 10 μm, at a layer thickness of up to 100 μm. The low-temperature bonding technique that is presented is particularly suitable for microstructure and microelectronics integration involved in MEMS packaging.

A mathematical model for designing and fabricating a hexagonal microlens array using a thermal reflow process was developed in this study. The experimental results proved that a hexagonal microlens array could be produced without a gap at each microlens periphery. A hexagonal microlens array with a higher fill factor was successfully produced. In this experiment, hexagonal photoresist columns were formed onto a silicon substrate made using a lithographic process. The hexagonal pattern was laid out in an ortho-triangle on a PET (polyethylene terephthalate)-based mask. Using precise temperature and time control during the thermal reflow process, a hexagonal microlens array with lateral honeycomb geometry was formed from the melted photoresist flowing outward simultaneously and uniformly. The surface tension effect transformed the photoresist column surface into a spherical profile. The error in the fabricated microlens characteristics was within ±3% between two theoretical models used to predict the photoresist column thickness and actual thickness. This model is feasible for fabricating various sized hexagonal microlens arrays.