This paper presents a novel fabrication process for micro metal parts using biologic etching method. The sheet metal parts can be etched by metabolism and biochemical reaction of microorganism. Thiobacillus ferrooxidans (T. f.) was employed in the machining process of metal components. By this bio-etching method, several shims with a thickness of 0.1mm and a diameter of only 2mm with a thickness of 0.07 mm and a diameter of 15mm and 16mm were fabricated.

Micro hobbing technology is an extension of traditional technology in small scale for processing micro gear. The micro gear shaft which module is 0.175mm is processed by micro hobbing technology. The tooth profile of the micro gear shaft is perfect and the tooth is divided evenly, the burr of the edge is small and the surface roughness is high enough to achieve the requirements of the micro gear shaft. In paper, the design of micro gear hob and the micro hobbing technology is the key factor to the manufacture of micro gear and is presented detailed. The result shows micro hobbing is a good way to process micro gear and it has some advantages including the high efficiency, accuracy in tooth profile, lower cost and widely range of suitable materials. micro-hobbing technology has significance value to research and can be applied in manufacturing the micro gear.

A bio-etching method using Thiobacillus ferrooxidans (T.f.) for processing micro-gear has been developed. The principle of bio-etching method is that certain microorganisms in nature consume some metal ions to be energy during their growth. The strain of Thiobacillus ferrooxidans consume elemental ferric and cooper ions as its energy source, so T.f. is selected as bio-etching tool, Leathen culture medium is selected as culture medium of T.f., and the thin copper sheet is used as the processed material. During the micro-gear is processed, firstly, thin copper sheet of 0.05mm is cleaned in the acid liquid and some materials such as dirt and grease are cleaned away, then, the anti-erode film is applied to the surface of thin copper sheet, then the surface of thin copper sheet is irradiated by ultraviolet under the condition that the surface is covered by mask film and developed, the anti-erode film that not covered by mask film will be dissolved and cleaned away, after that, thin copper sheet is put into the T.f. liquid and agitating, after the 3h, micro-gear is obtained. The result is showed that micro-gear can be processed by bio-etching method.

Reliability design is a new design theory and design methods with the modern science and technology developed. Food waste processing equipment is a new and efficient equipment used for food waste recycling. This paper briefly describes the design of mechanical reliability, and by describing the characteristics of food waste, described in the food waste processing equipment design, the need for the use of reliability design. To provide some basic reliability analysis for the future design of equipment.

With the three-dimensional computational fluid dynamics method, the airflow effects over the huge telescope assemble is investigated in this article. The distributing of velocity field and natural convection are studied by modeling and simulating the turbulent airflow of the huge telescope. Numerical simulations show the best observation direction is the 90o angle between the main optics axis and the horizontal line in which the air velocity distribution is the least. And the air temperature distribution and uniformity around the telescope are also provided by simulation.