The miniaturization of machines towards the micron and nanoscale requires the development of joint-like elements that enable and constrain motion. We developed a facile method to create colloidal joints, that is, anisotropic colloidal particles functionalized with surface mobile DNA linkers that control the motion range of bonded particles. We can control the flexibility of these colloidal joints by tuning the DNA linker concentration in the bond area.

Colloidal joints

We discovered, that the shape of the colloidal joint controls the range of motion of bonded particles through a maximisation of the bond area. Using spheres, cubes, and dumbbells, we experimentally realized spherical joints, planar sliders, and hinges, respectively. The reconfigurability and motion constraint offered by our colloidal joints make them promising building blocks for the development of witchable materials and nanorobots.