“Printing” on Polymer Single Crystals through Microregional Heating

Polymer single crystals are composed of well-ordered polymer chains and possess a characteristic symmetric shape. If one can precisely control the microregional morphology, polymer single crystals have the potential to be used as functional templates for applications like information storage or cell culture. However, with current experimental approaches, it is rather difficult to generate predictable structures of defined size within polymer single crystals. Here, we propose a research strategy based on a combination of fluorescence labeling and microregional heating by irradiation with focused red light. This approach enabled us to locally heat single crystals while simultaneously following the thereby induced changes via fluorescence imaging with a micrometer lateral resolution. We found that polymers diffused out of the heated region within a stacked single crystal and thereby produced a hole at the irradiated location. Our results revealed a competition of mechanisms of local melting and the generation of higher stacks of crystalline lamellae by recrystallization at the periphery of the molten region.