Abstract. The development of MEMS and Microsystems needs a reliable massproduction process to fabricate micro components with micro/nano scale features. In our study, we used the micro injection molding process to replicate micro/nano scale channels and ridges from a Bulk Metallic Glass (BMG) cavity insert. High density polyethylene (HDPE) was used as the molding material and Design of Experiment (DOE) was adopted to systematically and statistically investigate the relationship between machine parameters, real process conditions and replication quality. The peak cavity pressure and temperature were selected as process characteristic values to describe the real process conditions that material experienced during the filling process. The experiments revealed that the replication of ridges, including feature edge, profile and filling height, was sensitive to the flow direction; cavity pressure and temperature both increased with holding pressure and mold temperature; replication quality can be improved by increasing cavity pressure and temperature within a certain range. The replication quality of micro/nano features is tightly related to the thermomechanical history of material experienced during the molding process. In addition, the longevity and roughness of the BMG insert was also evaluated based on the number of injection molding cycles.

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A natural and synthetic layered silicate (LS) was modified with trihexyltetradecyl‐phosphonium tetrafluoroborate (an ionic liquid) via a cationic exchange reacation. The exchange reaction and loading of modifier was investigated using a combination of WAXD, inductively coupled plasma‐optical emmission spectroscopy (ICP‐OES) and thermogravimetric analysis (TGA). The thermal stability of the modified LS was enhanced by up to 150 °C, when compared with conventional quaternary ammonium cations, making melt mixing of such modified nanoclays possible with poly(ethylene‐terephthalate) (PET).

Planar-flow melt spinning (PFMS) is a single-stage rapid manufacturing/solidification technique for producing thin metal sheets or ribbons. Molten metal is forced through a nozzle onto the substrate where it freezes and is spun as ribbon product. A puddle of molten metal held by surface tension (capillarity) forms between the nozzle and substrate. An important measure of product quality is the uniformity of thickness along and across the ribbon. At small length scales, local thickness changes or surface defects are present that are undesirable. This work examines the cross wave, a well-defined periodic surface defect, seen when casting aluminum-silicon alloys. The presence of the defect is related to processing conditions and puddle dynamics. Motions of the puddle menisci are captured using high-speed video and analyzed for frequency content. A high frequency vibration of both menisci corresponds to the observed frequency of the surface defect. A scaling analysis reveals these motions to be capillary in nature and comparisons are made with two model problems of vibrating capillary liquids.