Abstract

Direct laser writing (DLW) in polymers is a rapidly evolving technology which allows fabrication of micro- and nano-structures for uses in such areas as microoptics, microfluidics, tissue engineering and others. Wet developing of the fabricated structures often results in permanent distortions which have been reported before [1] – sometimes as a useful phenomenon [2], but in most cases as an unwanted effect which should be overcome by shape precom-pensation [3] or other ways. On the other hand, we present reversible swelling and shrinkage of photoresists while they are still in the developer or other solvents and suggest ways to use it to our advantage. For example, a combination of solvent-sensitive and solvent-resistant parts in one structure (as was done by using 3D printing [4]) could provide the possibility to create micro-scale self-folding structures, that could work as self-regulating sensors. By placing the sensitive parts that can expand or contract depending on the surrounding medium at well chosen places the polymer could, for example, open or close a specific channel in a microfluidical chip.

© 2015 IEEE