Bending and buckling of rolled-up $SiGe∕Si$ microtubes using nanorobotic manipulation

Mechanical properties of individual rolled-up $SiGe∕Si$ microtubes are investigated experimentally using nanorobotic manipulation. By applying bending loads, individual $SiGe∕Si$ microtubes demonstrate various deformation modes with increasing bending angle. Remarkably, the tested microtubes resist fracture even when bent back onto themselves (180° bending angle). Axial compression tests of microtubes with different turns are also performed. Among those tubes, 1.6-turn rolled-up $SiGe∕Si$ microtubes show typical Euler buckling behavior when the load is larger than a critical load, which can be estimated by the Euler formula for columns.