Assembly and mechanical characterizations of polymer microhelical devices

Helical microstructures present large force and deformation range that give them good potential to become mechanical force sensors at the microscale. Various materials and processes have been proposed but their real life applications especially in wet/air environments are still very few mainly due to their mechanical robustness and non-linearity. Polymer microhelical devices are promising to overcome such mechanical limitations. Three-dimensional laser lithography allows fabrications of polymer helical microdevices with different geometries and designs but their mechanical properties were not yet known. In this paper, we present the fabrication of polymer microhelical device and in-situ scanning electron microscope micromanipulations for their mechanical property characterizations. It reachs mean stiffness up to 0.82 N/m (91.3 times higher than self-scrolling semiconductor microhelical devices which is 0.009 N/m), 68 % of elongation range and 12 μN of application force. The linearity of their mechanics can also reach up to 39 % of their elongation. Thanks to their excellent large range force/displacement mechanics and linearity, polymer micro-helical devices can further be applied as force sensors for measuring mechanical properties of deformable biological objects or soft nanostructures.