Design and analysis of an under-actuated XYθ stage for automated tissue indentation

Micro manipulation is essential for tissue indentation tasks in micro-scale experiment, and microscopes must be equipped with multi degree-of-freedom (DOF) stages to accurately reach the regions of interest (ROI). Current microscope stages have three main drawbacks when applied to material characterization tasks. First, most microscope stages are designed for 2- or 3-DOF manipulation, lacking the ability to rotate the specimen. Second, the average micro-positioning stage is manually adjusted, and finally most stages accomplish either a large travel range or sub-micron resolution manipulation, but not both. These limitations pose a challenge for phenotyping diseases using quantitative mechanical signatures. This research is motivated by the need for improved accuracy in breast cancer detection. The following work aims to improve upon current micro-positioning stages by allowing for 4-DOF motion (XYθ for in-plane motion and Z direction indentation) and the ability to employ a variety of devices for material characterization. The ability to rotate the specimen will provide improved accuracy in reaching the ROI and robust measurement in uncertain specimen environments. The work described herein explains the design and analysis toward an under-actuated micro-positioning stage for automated tissue indentation.