The kind of micro-/nano-meter precision actuator in cludes a piezoelectric one, an electric deformation one, a magnetic deformation one, a mechanical one, and a mechanical and electrical one. This paper puts forw ard ...The kind of micro-/nano-meter precision actuator in cludes a piezoelectric one, an electric deformation one, a magnetic deformation one, a mechanical one, and a mechanical and electrical one. This paper puts forw ard a mechanical and electrical step actuator of nanometer precision, which cons ists of a step motor of large fine-dividing number of step angle, shaft couplin gs, a decelerator of large decelerating ratio, a screw mechanism and a pole of U shape, and has the minimum step displacement of 10 nm, the step displac ement precision of 1 nm, the step frequency of 4 kHz, the maximum loadability of 20 kg. In order to achieve the nano displacement of nano precision by this actu ator, the theoretical analysis of stress and strain must be made on the transmit ting course of nano displacement of the actuator, and their numerical simulation is done by computer. The paper establishes the constitutive equation of 3-D stress and the strain co ordinate equation of the composing system of the nanometer precision actuator. A s a result, the theoretical relation among stress and strain and displacement is set up. The torque of the step motor produces a thrust to transmit the displace ment of the above system of the parts and assemblies to output the needed nano d isplacement. In the case of concrete analysis and calculating, the comparing met hod of film-roof is applied to analyze and calculate the motor axis, decelerato r axes, the screw pole and the nut. The analysis method of plane stress and stra in is used to analyze and calculate the shaft couplings and gears. The analysis method of beam stress and strain is used to do the pole of U shape. These calcul ation is belong to the physical non-linear problem. Under the condition of smal l deformation, the analysis way of the finite element can be combined with the a bove analyses and calculations. The elementary analysis results show that the na nometer precision actuator can be applied in STM nanofabrication.展开更多
Three dimension free curves find wide applications in engineering. There is no problem to express them exactly mathematically, but th e reportage has not been done on the investigation of precision analysis of thre e-...Three dimension free curves find wide applications in engineering. There is no problem to express them exactly mathematically, but th e reportage has not been done on the investigation of precision analysis of thre e-dimension free curves nanofabrication. Nanofabrication Precision includes the geometrical precision and the precision of driving system (below simply cal led the system precision). This paper submits the precision analysis method of c urve normal vector to analyze geometrical precision. Take an aspherical surf ace for example, it can be fitted and constructed by tensor product parameter cu rves, such as linear drawing curves, straight veins curves, rotating curves, swe eping curves, DUCT curves and Geomap curves. Then the curves of the aspherical s urface is iterated and modified to select the best fitted curves of the aspheric al surface. Finally, the geometrical precision of perfect approximate aspherical surface fitting has been sought. This kind of geometrical fitting construction is very important. Another is the system precision, which contains axial position precision, line p recision, and twisting and swinging precision, etc. The paper adopts the theory of precision optimum match (Prof. Wang Er-qi first put forward in 19 83) to allocate precision optimumly. The minimum cost is used as an objective fu nction, and weight method matches the precision. To obtain the optimum match combination of the minimum cost design parameters and every composing element t olerance, the precision is iterated and sought optimumly to design the system op timumly. The theoretical analysis shows that it’s feasible to control three dim ension free curves nanofabrication within nanometer scale precision.展开更多
文摘The kind of micro-/nano-meter precision actuator in cludes a piezoelectric one, an electric deformation one, a magnetic deformation one, a mechanical one, and a mechanical and electrical one. This paper puts forw ard a mechanical and electrical step actuator of nanometer precision, which cons ists of a step motor of large fine-dividing number of step angle, shaft couplin gs, a decelerator of large decelerating ratio, a screw mechanism and a pole of U shape, and has the minimum step displacement of 10 nm, the step displac ement precision of 1 nm, the step frequency of 4 kHz, the maximum loadability of 20 kg. In order to achieve the nano displacement of nano precision by this actu ator, the theoretical analysis of stress and strain must be made on the transmit ting course of nano displacement of the actuator, and their numerical simulation is done by computer. The paper establishes the constitutive equation of 3-D stress and the strain co ordinate equation of the composing system of the nanometer precision actuator. A s a result, the theoretical relation among stress and strain and displacement is set up. The torque of the step motor produces a thrust to transmit the displace ment of the above system of the parts and assemblies to output the needed nano d isplacement. In the case of concrete analysis and calculating, the comparing met hod of film-roof is applied to analyze and calculate the motor axis, decelerato r axes, the screw pole and the nut. The analysis method of plane stress and stra in is used to analyze and calculate the shaft couplings and gears. The analysis method of beam stress and strain is used to do the pole of U shape. These calcul ation is belong to the physical non-linear problem. Under the condition of smal l deformation, the analysis way of the finite element can be combined with the a bove analyses and calculations. The elementary analysis results show that the na nometer precision actuator can be applied in STM nanofabrication.
文摘Three dimension free curves find wide applications in engineering. There is no problem to express them exactly mathematically, but th e reportage has not been done on the investigation of precision analysis of thre e-dimension free curves nanofabrication. Nanofabrication Precision includes the geometrical precision and the precision of driving system (below simply cal led the system precision). This paper submits the precision analysis method of c urve normal vector to analyze geometrical precision. Take an aspherical surf ace for example, it can be fitted and constructed by tensor product parameter cu rves, such as linear drawing curves, straight veins curves, rotating curves, swe eping curves, DUCT curves and Geomap curves. Then the curves of the aspherical s urface is iterated and modified to select the best fitted curves of the aspheric al surface. Finally, the geometrical precision of perfect approximate aspherical surface fitting has been sought. This kind of geometrical fitting construction is very important. Another is the system precision, which contains axial position precision, line p recision, and twisting and swinging precision, etc. The paper adopts the theory of precision optimum match (Prof. Wang Er-qi first put forward in 19 83) to allocate precision optimumly. The minimum cost is used as an objective fu nction, and weight method matches the precision. To obtain the optimum match combination of the minimum cost design parameters and every composing element t olerance, the precision is iterated and sought optimumly to design the system op timumly. The theoretical analysis shows that it’s feasible to control three dim ension free curves nanofabrication within nanometer scale precision.
