Strain-induced self-rolled-up microtubes for multifunctional on-chip microfluidic applications.

On-chip microfluidics are characterized as miniaturized devices that can be either integrated with other components on-chip or can individually serve as a standalone lab-on-a-chip system for a variety of applications ranging from biochemical sensing to macromolecular manipulation. Heterogenous integration with various materials and form factors is, therefore, key to enhancing the performance of such microfluidic systems. The fabrication of complex three-dimensional (3D) microfluidic components that can be easily integrated with other material systems and existing state-of-the-art microfluidics is of rising importance. Research on producing self-assembled 3D architectures by the emerging self-rolled-up membrane (S-RuM) technology may hold the key to such integration. S-RuM technology relies on a strain-induced deformation mechanism to spontaneously transform stacked thin-film materials into 3D cylindrical hollow structures virtually on any kind of substrate. Besides serving as a compact microfluidic chamber, the S-RuM-based on-chip microtubular architecture exhibits several other advantages for microfluidic applications including customizable geometry, biocompatibility, chemical stability, ease of integration, uniform field distributions, and increased surface area to volume ratio. In this Review, we will highlight some of the applications related to molecule/particle sensing, particle delivery, and manipulation that utilized S-RuM technology to their advantage.