The accurate and rapid replication of micro-ano-features with a high aspect ratio (AR) is one of the main challenges in micro-molding. In this work, the micro-injection-compression molding (μ-ICM) process and a new monitoring technique were combined to replicate micro-features with controllable and detectable ARs. Using a surface strain sensor mounted on the external surface of the mold, indirect acquisition of accurate cavity pressure during post-filling was realized, based on the specific pressure distribution on the mold predicted by the Hele-Shaw flow simulation. The feasibility of the proposed measuring technique was verified both numerically via finite-element analysis for the mold strain and experimentally by comparing cavity pressure profiles acquired directly and indirectly. Furthermore, primarily dominated by the maximum cavity pressure appearing during post-filling, the AR of molded polystyrene micro-feature in the downstream of cavity could be monitored via this technique with certain accuracy, and controlled by manipulating the compression force. Also the qualitative AR results of the other upstream micro-features were detectable in μ-ICM. Within a cycle time of 26 s, a maximum AR of about 12.1 was achieved on micro-features, indicating the potential for the mass production of complex micro parts applying μ-ICM.
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