Papers by Author: Simon S. Ang

Abstract: Microfluidic channel and micro-cavities were fabricated from polyhydroxyalkanoate biodegradable polymer using a direct 20ns, 248 nm excimer laser writing method. First we give a design of the micro-analytical device; second we discussed the laser ablation of biodegradable ppolymer material. The morphology, dimensional accuracy, and surface conditions of the fabricated micro-devices were studied using atomic force microscopy, scanning electron microscopy, optical microscopy, and X-ray photoelectron spectroscopy. Melting of the biodegradable polymer was observed at a fluency of 50mJ/cm2 while ablation was observed at a fluency of 100mJ/cm2.The different width between bottom and top surface are studied in our research. The particle deposited on the polymer surface is seen from the SEM of 248nm laser ablation of PHA. However, the direct burning of PHA can be seen from the optical photo by 355nm laser. Compare to results of PHA with two different lasers, we can see that the 248nm laser is a suitable choice.

Abstract: Functional manufacturing technologies are becoming more and more important to the manufacturing industry and research. As promising categories of functional manufacturing, micro and nano manufacturing have received steadily growing interests in recent years. In this paper, as typical examples to demonstrate micro and nano manufacturing, our work on microthruster, nano energetic material, and micro/nano initiator is presented. Microspacecraft is one application of microsystem in space. In a microspacecraft, a micropropulsion system is required for station keeping, attitude control, and orbit adjust. New silicon and ceramic microthrusters are described. Energetic materials including propellants, explosives, and pyrotechnics have found diverse applications. Nano energetic materials (nEMs) have improved performances in energy release, ignition, and mechanical properties compared to their bulk/micro counterparts. A novel nano Al and CuO nanowire based nEM is discussed. Electro-explosive devices (EEDs) activated by electrical energy are used to initiate an explosive, burning, electrical, or mechanical train. EEDs have found numerous applications in triggering the inflation of airbags in automobiles, micropropulsion, and arm fire/safe devices for ordnance systems. An innovative EED is developed by integrating Al/CuO based nEM with a Au/Pt/Cr micro heater on a substrate.

Abstract: Multilayer ceramics based on the low-temperature co-fired ceramics (LTCC) are gaining increasing interests in the manufacturing of highly-integrated systems for microelectronic and micro-system applications. The polishing experiments of sintered LTCC using a custom-built precision polishing machine are reported in this paper. First, a micro-fluidic distributor was fabricated using LTCC. Then, the polishing of this meso-MEMS system was studied using several polishing parameters. By optimizing the polishing parameters, the surface roughness can be reduced to 4 nm.