Duo-mold imprinting

PDMS posts (450 nm in height) prepared by DTM [24] (b) complex 3D structures (inverted Z-shape) fabricated with PMMA using DMI [29]. (Reproduced with permission from [24]. 

Copyright (2005) American Chemicai Society Reproduced with permission from [29]. Copyright (2006) American Institute of Physics.) 

The success of DMI depends on three factors the accuracy of alignment of the two molds the preferential demolding step, and the final pattern transfer to the substrate with minimal deformation of the polymer structures [29]. 

Printing on Topographies (Muhilayer Printing) and on Flexible Substrates 

One of the main features of TP methods is the abUity to pattern on nonplanar or flexible surfaces (such as polymer membranes) and on topographies or previously patterned surfaces. The last feature may be repeated (with some processes, indefinitely), creating multilayered 3D structures and hierarchichal structures. 

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Kong et al. [27] developed a TP technique where the substrate is also a patterned surface, forming therefore a polymeric film patterned on both surfaces. The technique is called duo-mold imprinting (DMI) and may be used to generate free-standing 3D structures as well as supported structures with sealed cavities and/or with two different polymers (Figure 5.5b) [28, 29]. 

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