Papers by Author: A.J. Wang

Abstract: Bonds of electroplated diamond tools are investigated through the studies of microstructures and properties. Three coatings for tool bonds, nickel, nickel-cobalt and bright nickel, were fabricated with electrodeposition processes, and were heat-treated with different temperatures. The hardness and microstructures of coatings were measured and observed. Optical glass K9 was machined with fabricated electroplated diamond tools to compare material removal rate and grinding ratio. The grain sizes of three bond coatings are different. The laminar structures of nickel-cobalt and bright nickel coatings turn to fine columnar structure after heat treatment processes. With heat treatment of 200°C temperature, bright nickel electroplated diamond tool presents highest values of material removal rate and grinding ratio. The research results show that better microstructures and property of bond for electroplated diamond tool can be obtained by selecting proper electroplating technology and heat treatment processes.

Abstract: A new method to fabricate porous chitosan nerve conduits with multi-channels was described. A uniquely designed mold was composed of 7-50 stainless steel needles and a set of plastic pedestals. Porous or imperforate chitosan tubes with 2-5mm inner diameter and 0.2-1.0 mm wall thickness were made firstly. The chitosan tubes were injected with 3% chitosan gel. The stainless steel needles longitudinally perforated through the chitosan tubes filled with chitosan gel, and the plastic pedestals were used to fix the needles. Lyophilization was used to finish fabrication. The diameter of channels was 0.2-0.4mm. Swelling property and biodegradability of Multi-channeled chitosan conduits were investigated. Wright’s staining and scanning electron microscope (SEM) were used to observe spread and proliferation of Neuroblastoma cells (N2A, mouse) on the conduits. It is promising that the porous chitosan nerve conduits with multi-channels are used as nerve tissue engineering scaffolds in repair of peripheral nerve and spinal cord injuries.