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Construction of an activated three-dimensional (3D) tissue outside the human body is highly desirable, and it is expected that micro-manipulation should be used to construct 3D organisations. In micro-manipulation, it is difficult to obtain depth information, as an object is usually observed using an optical microscope. Thus, empirical techniques that require extensive practice are employed. To overcome this problem, a system that can perform real-time 3D measurements is indispensable. In this study, an improvement in the speed of 3D measurements in a microhabitat is obtained, which would facilitate micro-manipulation and the construction of 3D cellular organisations.

Toroidal-like sheroids are important in the field of tissue engineering. However, the formation processes of toroidal-like spheroids may not be considered efficient, as most of them are manual. In this paper, we suggest the possibility and effectiveness of applying microfluidics for formation of toroidal-like spheroids. The concept of our method is that cells are compressed by rotational flow in a microchannel and dielectrophoretic force. Some types of microchannels that can generate rotational flow were designed and were analysed with flow analysis software. A superior microchannel was fabricated, and a flow of NIH3T3 cell suspension was supplied to the channel. As the flow rate was changed, the cells were rotated in the microchannel according to our concept, and approximately 30% of them remained in the channel. This result supports our concept: toroidal-like spheroids can be formed under the influence of forces of rotational flow and dielectrophoresis.

In micro-manipulation, releasing of micro-objects is a challenging work due to the difficulty of controlling adhesion forces. To overcome the adhesion force and place micro-objects with high position accuracy, in this paper, local stream generated by high-speed motions of an end-effector is proposed. A compact parallel link creates 3D end-effector motion at high-speed without uncontrollable vibration, which means local stream can generate enough force in a 3D direction to separate micro-objects. Applying the local stream created by the right end-effector, micro-objects including 55 µm microbeads and NIH3T3 cells attached to the left end-effector were released. To verify the placing positions of the objects, we compared four motions, 1D motions (X- and Z-directions) and circular motions (clockwise and counterclockwise directions), by analysing the trajectory of the objects after separation. From these results of experiments, we concluded that the circular motion (CCW) detached micro-objects in the nearest position from the end-effector.

For autonomous robots, the ability to manipulate unknown objects is pivotal to successfully operate in a complex environment. This paper presents a novel multi lighting two-step method for unknown objects segmentation using albedo characteristics of object shape. The authors address the task of detecting unknown multi colored objects of interest, specifically ones that are being seen for the first time and located in the proximity of unidentified obstacles. Illumination at different wavelengths and angles are projected by a robot, thus acquiring additional information about the scene and exploiting it for successful unknown objects segmentation. By analyzing shades and reflections of a scene's objects, we were able to form and identify true edges and visually separate items of interest. The proposed method does not require predefined models of target objects and assumes no previously assigned targets pose. The technique was validated by presenting promising experimental results using an autonomous robot manipulator successfully performing unknown objects segmentation from cluttered environments.

Stable grasping of micro-objects at high speed is a desired feature for micromanipulation systems. At high speed, however, the residual vibration tends to be greater. In this paper, we analyse the residual vibration of the end effector of the microhand during the high-speed grasping motion. Based on the analysis results, we propose suppression of residual vibration in two steps. First, the stiffness of the end effector is increased by structural design. Second, feedforward control is implemented since the behaviour of the vibration can predicted for the specific conditions. Preliminary experimental results show that the settling time decreases by 74% and the amplitude of the vibration by 47%.

Two proposals on mobile manipulation of “limbed robots”-defined as robots which have both arms and legs-are described. 1) “Limb Mechanism”, using one linkage for both legged locomotion and arm manipulation, enlarges arm's working space and augments arm's versatility in mobile manipulation. Based on this concept, a six-limb robot is developed. 2) Coordinating with the arm motion for performing objective tasks, the legs autonomously change some motion patterns such as standing and stepping; that enables dexterous, stable and efficient manipulation by the arms. This control method is applied to humanoid robots, which have two arms and two legs.