Automatic Cell Assembly by Twofingered Microhand We have successfully achieved manipulation and assembly of microbeads having the size of 100xcexbcm diameter by hemispherical endeffectors with high stability and accuracy. The motivation of achieving assembly of actual cells lies in the great significance of it in tissue regeneration and cell analysis. Firstly, the most difficult problem we need to solve is the releasing problem caused by adhesion force. The viscosity on cell surface is much larger than the microbeads which makes cell releasing challenging. Secondly, the cell can generate its deformation, then contact area with endeffector will change during grasping process. This may influence the adhesion force and also bring problem to releasing. Thirdly, cell is much smaller, around 15xcexbcm in diameter, so we need to fabricate smaller endeffector to achieve successful manipulation and ensure the stability in the meantime. In this paper, we realize the manipulation by decreasing the adhesion forces and apply vibration to release a cell stably. We found the appropriate scale size for the endeffector is around 10xcexbcm diameter. It can not only grasp a 15xcexbcm cell but also bring little interference to the environment. As a demonstration of the proposed manipulation method, the repeated experiments were conducted to explore the dependence of adhesion force on the grasping distance, which can be helpful in the improvement of successful rate. Finally, we achieved automatic cell assembly using Hela cells.

Automated MacroMicro Manipulation for Robotic Microinjection with Computer Vision Extensive research efforts have been made toward automating the microinjection of biological cells by leveraging microrobotic technologies. However, to best knowledge of the authors, there is no report on the automation of the timeconsuming process: moving the injection tools (a micropipette, a grippers, etc.) and cells into the field of view (FOV) of microscope from the macro FOV(outside the microscopic FOV). This paper presents a novel macromicro conversion strategy, and a grid detection and positioning algorithm to automate the timeconsuming step of moving the injection tools and cells to the microscopic FOV. The proposed solution can free the technician from the laborious handeye coordination operations for moving the injection tools and cells to the target position within the microscopic FOV. Furthermore, this paper proposes an autofocusing algorithm to automate the operation step: moving down the gripper from the air outside the culture media and then precisely clamping a cell in the liquid environment for injection. In the proposed solution, the active windowbased autofocusing algorithm is developed to solve the challenging problem: the image information is lost due to the xe2x80x9cviscous effectxe2x80x9d taking place when the gripper jaw touches the water surface. The proposed solutions are tested and validated by the microinjection experiments of zebrafish embryos using the inhouse develop microrobotic system. The technologies and strategies proposed in this paper significantly improve the automation level of the cell microinjections, and can be easily extended to any other micromanipulation of biological cells.