Microfluidic systems have been widely investigated for bioanalysis, organic and nanoparticle synthesis. The potential of microfluidics in other areas of technology, such as microfluidic adhesion, microsolidics and self-healing materials has only begun to be realized and investigated very recently. Here, we report novel microfluidic materials in the form of flexible sheets that can be solidified on demand to yield specific shapes. They are based on microfluidic channel networks in polydimethylsiloxane (PDMS) filled with photo-curable polymers. When the microchannel networks are shaped and exposed by UV light, the photoresist inside the channels is solidified and acts as endoskeleton within the PDMS layer, acquiring the pre-arranged shape. This bending and stretching moduli of the materials with solidified endoskeleton increases drastically and once the external stress is removed, the memorized shapes are recovered. The permanent preservation of the shape of solidified microfluidic sheets could be used in making instant packages and supports on demand, creating "exoskeletons" for delicate package contents and multiple other applications.