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This paper analyzes the reason why the polymer is melted on a non-forming surface during ultrasonic embossing and proposes a method to inhibit the polymer melting.On the basis of the heating mechanism of ultrasonic,it points out that the polymer melting phenomenon on non-forming surface is resulted by the friction in a horn-substrate interface.Then,it proposed the method"two interfaces of different friction coefficients"to inhibit the polymer melting and implemented the method by coatings surface protection films on the non-forming surface.To optimize the protection films,and the influences of the four coating film conditions on the softening time are examined through Taguchi method.The results show that the Sekisui#622E-50 film shortens the softening time by 3.4sandthe Sekisui#622WB film reduces the softening time error by 0.64 s.It demonstrates that surface protection films coated can avoid polymer melting on the non-forming surface,and improve the process replication ability and the process stability in ultrasonic embossing.

A thermal-assisted ultrasonic embossing method was proposed based on silicon molds to replicate thermoplastic substrates in a low cost and high efficiency.The ultrasonic vibration was applied to the mold-polymer interface to heat the polymer rapidly to the embossing temperature.To reduce the risk of damaging the mold,the die was preheated to a temperature which is 35-50℃ below the glass transition temperature(Tg)of the polymer.Then,the influences of the ultrasonic amplitude, ultrasonic force,ultrasonic time,and the thermal-assisted temperature were studied by orthogonal array experiments to reveal the mechanism of ultrasonic embossing.The influence of the substrate thickness was also investigated.The experimental results show that the most important parameter for replication is the thermal-assisted temperature,follows by the ultrasonic amplitude.Moreover,the ultrasonic force is the most important parameter for replication uniformity,while the thinner polymersheets are more conducive to be replicated under the same circumstances.With the optimized parameters,the replication accuracy has reached 99%on a Polymethyl Methacrylate(PMMA)substrate,and the cycle time is less than 50s.All theses studied show that thermal assisted ultrasonic embossing has high replication efficiency and is a potential way to mass formation of polymer microstructures.

In order to improve the resolution of an Extreme Ultraviolet(EUV) photon counting imager,this paper analyzed the influence of the crosstalk between Wedge Strip Zigzag(WSZ) anodes and the false trigger resulted from out-range signals on image quality.First,the reasons which caused the crosstalk were analyzed,and the range of crosstalk coefficient and its optimum value were determined by measuring interelectrode capacitance.Then,the crosstalk coefficient was used to process photons and determine a proper energy interval(upper and lower limit).Finally,the image obtained in the setting energy interval was compared with an original image.The comparison shows that the image quality has been improved obviously.The results demonstrate that the image edge becomes stronger further and image resolution is improved by eliminating the crosstalk between WSZ anodes and removing fake data from real data.

The slippage between discs and rail is one of important factors for the measurement accuracy of an involute.However,control of frictions effectively can modify the slippage of discs.In the paper,frictions between discs and rail are analyzed respectively when a cord and a belt are used to drive the discs to roll.According to the analysis and experiment,it shows that if measuring forces are 0.7 N and 0.2 N and the base discs is drived by the cord and belt,frictions are 0.02 N and 0.07 N respectively,for the base disc clockwise rolled;where the effect of the slippages of based discs on the involute measurement can be ignored.Moreover,the slippage can also be reduced by increasing the weight of base disc groups,and measurement difference of involute is 0.06 μm when the rolling directions of the base discs are different.

In order to improve the efficiency of ultrasonic bonding process for a polymer Electro-Mechanical System(MEMS) and to prevent the flow of polymer under a high temperature,a micro energy director array was proposed.Based on the experiment of PMMA micro-pipe sealing,the influence of micro energy director array on the process of ultrasonic sealing was studied.Five kinds of micro energy directors with different heights were fabricated on the sealing surface by a hot embossing technique.The method of ultrasonic precise sealing based on acoustic transfer efficiency feedback was used in the experiment to study the influence of the height of the micro-array structure on the quality of ultrasonic sealing and to observe the wetting behavior of micro-array structure.Experimental results indicate that the ultrasonic energy to achieve complete connection increases with increasing the height of micro energy director array.The micro energy director can control the flow of the melting-polymer effectively and can obtain the uniform sealing surface and high quality precise sealing.