LAUSR

Abstract Micro features on surfaces are critical for the functionality of a product, such as micro channels for a microfluidic chip and micro lens arrays for an artificial compound eye lens. In the present work, we design a series of microfluidic and microstructured surface patterns to evaluate the influence of variotherm and vacuum venting on replication integrity of micro features. By using a process monitoring system, including machine process and cavity pressure/temperature measurements, the influence of warm and cold circuit settings, and vacuum venting are characterised in terms of injection pressure, cavity pressure and mould–polymer interface temperature. These are then correlated with the replication integrity of micro features by assessing feature replication height, cross-section area and surface morphology. The performance of anti-stick coatings on a micro mould tool insert was also characterised in terms of moulding cycles. After a series experiments and optimisation, we have significantly enhanced feature replication with 100% replication of proposed features without either significant distortion or tearing, which cannot easily be achieved using conventional injection moulding. Additionally, we have successfully moulded features having good integrity and a maximum aspect ratio of up to 10 at a width of less than 8 μm over areas as large as 5.25 mm2.