Precision positioning stages are often central to science and technology at the micrometer and nanometer length scales in diverse fields such as microscopy, robotics, automation and metrology. These stages are used to hold in place, or move in a specified manner, a piece of equipment or sample. Therefore, compact multi-degree-of-freedom stages with large dynamic range are especially desirable.However, most positioning technologies demand large compromises to be made on one or more of these fronts.
In recent work that has appeared in Nature Communications, researchers from Indian Institute of Science (IISc) report compact, diamagnetically levitated positioning stages that achieve large-range, six degrees-of-freedom (DOF) positioning with nanometre-scale precision. They demonstrate this DOF positioning with low cross-axis motion, large range and nanometer-scale resolution. They show that the in-plane linear motion range of 5 mm with positioning precision is better than 1.88 nm, out-of-plane range of 900 µm, and angular motion range of 1.1 radian with a resolution of 50 micro-radian.
Compared to diamagnetically levitated stages reported in literature, the proposed stages achieve between one to two orders of magnitude improvement in payload carrying capability, positioning stability, cross-axis motion, out-of-plane positioning range, in-plane angular positioning range and precision. In contrast to stages based on active magnetic levitation and piezo-electric actuation, these stages achieve comparable linear positioning performance and two orders of magnitude higher in-plane angular range and in a volume that is at least one order of magnitude less.
These stages, therefore, offer a combination of range, resolution, and low volume that other state-of-the-art positioning technologies cannot individually achieve. This creates new possibilities for applications in micro and nanorobotics, scanning probe microscopy and optical alignment.
Fig. (a) Photograph of the multi-zone positioner (b) graph showcasing the range (5mm) of positioner (c) graph showing 50nm stepping by the positioner”>
K S Vikrant and G R Jayanth, Diamagnetically levitated nanopositioners with large range and multiple degrees of freedom, Nature Communications, Article No 3334, 2022.
Also featured in Editors’ Highlights webpage: https://www.nature.com/collections/bjiiabbacg