PMMA表面微结构阵列微波辅助热压成型研究

doi:10.3901/JME.2025.23.250

摘要/Abstract

摘要： 热压成型是实现聚合物微结构元件连续成型的重要技术，但其加热环节仍依赖传统电阻/红外加热，难以兼顾材料的加热速率和温度均匀性。鉴于此，提出一种用于聚合物元件快速成型的新型微波辅助热压方法。该方法以微波磁控管为唯一功率源，通过吸波微结构模具与透波隔热套筒组合设计，实现热压组件的靶向快速加热；再通过精确电伺服加载，实现聚合物表面结构复制成型。以典型热塑性聚合物PMMA为例，在不同加热/加载条件下开展了微环阵列的微波辅助热压工艺试验，结果表明：(i)微波可在低功率(600 W)、短时间(8 s)内将SiC模具加热至200℃，平均加热速率(25℃/s)相当于常规电阻/红外加热速率(<5℃/s)的5倍以上；上下模具的内部温差不超过2.0℃，温度均匀性与常规方法相当。(ii)增加热压温度、热压速度和保压时间均有助于提升微环阵列的平均高度，但增幅逐渐减小。(iii)采用优选工艺参数(热压温度180℃、热压速度0.06 mm/s、保压时间250 s)可获得98.39%的微环充型率，并在PMMA表面成功复制出规整的百微米级直槽阵列和单微米级锥形阵列。这些结果表明所提出方法能实现聚合物预形体的快速均匀加热，适用于不同尺度不同类型微结构的精密成型，为微光学和微流控元器件的绿色高效制造提供了新途径。

关键词: PMMA, 微结构阵列, 微波辅助热压, 加热速率, 充型率

Abstract: Hot embossing serves as an important technology for continuous production of polymer microcomponents, yet its heating stage still relies on conventional resistance or infrared heating, which struggle to balance heating rate and temperature uniformity. To address this limitation, this study proposes a novel microwave-assisted hot embossing (MHE) process for rapid polymer microfabrication, using microwave (MW) magnetrons as the sole power source. In MHE, two MW-absorbing microstructured molds and an MW-transparent insulating sleeve are first designed to achieve targeted and rapid heating of embossing parts, followed by precise servo-electric loading to replicate mold microstructures onto polymer surfaces. Using the typical thermoplastic polymer—polymethyl methacrylate (PMMA), MHE experiments of microring arrays are conducted under varied heating/loading conditions. The results indicate that: (i) MHE enables rapid heating of SiC molds to 200 ℃ at low power (600 W) within 8 s, and its average heating rate (25 ℃/s) is over five times faster than conventional heating (<5 ℃/s); the temperature difference between the upper and lower molds is down to 2.0 ℃, demonstrating the temperature uniformity comparable to conventional heating. (ii) Theaverage height of PMMA microrings increases with the increasing embossing temperature, embossing speed, and holding time, albeit with diminishing returns. (iii) Using the preferred processing parameters (embossing temperature 180 ℃, embossing speed 0.06 mm/s, holding time 250 s), the filling ratio of the microring replica reaches 98.39%, and regular hundred-micrometer-scale straight grooves and single-micrometer-scale conical arrays are successfully replicated onto PMMA surfaces. These results show that the proposed method can achieve rapid and uniform heating of polymer preforms, thus allowing for precise replication of multi-scale and muti-type surface structures, and offering a promising pathway for green and efficient manufacturing of microoptics and microfluidics components.

Key words: PMMA, microstructure array, microwave-assisted hot embossing, heating rate, filling ratio

中图分类号:

TG156

罗红, 宾翔, 余剑武, 钱军. PMMA表面微结构阵列微波辅助热压成型研究[J]. 机械工程学报, 2025, 61(23): 250-258.

LUO Hong, BIN Xiang, YU Jianwu, QIAN Jun. Study of Microwave-assisted Hot Embossing of PMMA-based Microstructure Arrays[J]. Journal of Mechanical Engineering, 2025, 61(23): 250-258.

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