There is no previous definition.
Micro-motors. There are two maw types of micro-motors: electromagnetic and piezoelectric. A good review of electromagnetic rnicro-motors is reported in [17j, where their main types are illus-trated (variable reluctance, induction and perma-nent-magnet micro-motors), the permanent-mag-net micro motor being confirmed robe the best in terms of developed power. These electromagnetic micro-motors operate the same as the bigger ones in the macro-world, but with their parts reduced to the minimum possible size. Numerous compa-nies are selling electromagnetic micro-motors, among which the Faulhaher Group and Maxon Motor stand out.
On the other hand, piezoelectric micro-motors are based on the change in shape of a piezoelectric material. The motion is produced from the ultra-sonic vibrations of the material when applying an electrical field. There are both linear- and rotary-motion micro-motors (Fig. 19-5).
(Qin Y. Micromanufacturing Engineering and Technology page:319)
Absolute viscosity (Materiak Property)
There is no previous definition.
The absolute viscosity is the ratio of shear stress to shear rate. It is the propeoy of internal resistance of a fluid that opposes the relative motion of adjacent layers Basically it is the tangential force on a unit area of either of two parallel planes at a unit distance apart, when the space between the planes is filled with fluid (in question) and one of the planes moms with unit velocity in its own plane relative to the other.
There is no previous definition.
In the late 1980s, the design an manufacturing tool set developed for VLSI was adapted for use in a field called micro electromechanical systems (MEMS). These systems interface wilh both electronic and nonelectronic signals a. interact with the nonelectrical physical world as well the electronic world by merging signal processing with sensing and/ or actuation. Instead of handling only electrical signals. MEMS also bring into play mechanical elements. some with moving parts, making possible systems such as miniature fluid-pressure arid flow sensors, accelerometers, gyroscopes, and microoptical devices. MEMS are designed using computer-aided design (CAD) techniques based on VLSI and mechanical CAD systems and are typically batelkfabricated using VLSI-based fabrication tmds. Like ICs. MEMS are progressing smaller sizes. high. speeds, and greater functionality.
MEMS already have a track record of commercial success that provides a compelling case for further development (e.g., pressure-sensing. acceleration sensing. a. ink-jet printing). Like any developing field. however. connnercial successes in the MEMS field coexist with products still under development that have not yet establistied a la, customer base (e.g., MEMS display systems and integrated chemical-analysis systems).
( National Research Council, Microelectromechanical Systems: Advanced Materials and Fabrication Methods, page:1)
Chucking Machine ( Automotion Machine)
There is no previous definition.
As the name suggests, a chucking machine (nicknamed chucker) uses a chuck in its spindle to hold the workpart. The tailstock is absent on a chucker, so parts cannot be mounted between centers This restricts the use of a chucking machine to short, light-weight parts. The setup and operation are similar to a turret lathe except that the feeding actions of the cutting tools are controlled automatically rather than by a human operator. The functional the operator is to load and unload the parts
(M.P. Fundamentals of Modern Manufacturing 3th edt, Page:514)
Powder Injection Molding (Manufacturing Technique)
The binder in powder injection molding acts as a carrier for the particles. Its func-tions are to provide proper flow characteristics during molding and to hold the pow-ders in The molded shape until sintering. The five basic types of binders in PIM are (1) thermosetting polymers, such s phenolim, (2) thermoplastic polymers, such as polyethylene, (3) water, (4) gels, and (5) inorganic materials [6]. Polymers are the most frequently used.
Powder injection molding is suited to part geometries similar to those in plastic injection molding It is not cost competitive for simple axisymrnetric parts, because the conventional press and sinter process is quite adequate for these cases PIM seems most economical for small, complex par sof high vain. Dimensional accuracy is limited by the shrinkage that accompanies densifimtion during sintering.
(M.P. Fundamentals of Modern Manufacturing 3th edt, Page:352-353)
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