Architecture of Hybrid Two-fingered Micro Hand: Analysis, Optimization, and Design

iii Summary In last few years, the demand for micro motion devices increases in many industrial applications; especially fields of assembling micro machines, manipulating biological cells, and micro-surgical operation. As a consequence, there is an urgent need to develop dexterous micro-manipulators. However, the field of manipulating microscopic objects places hard requirements on the design process such as knowing the dynamics of microscopic objects, actuation mechanisms, and joint types that can be easily realized on a miniature scale. Therefore a successful design of micro-manipulator mechanism has to fulfill the above mentioned design requirements. This thesis addresses the development process of a compact and yet economical chopstick-like two-fingered micro-manipulator hand based on hybrid structure actuation mechanism. The proposed micro-manipulator hand consists of two modules connected serially back to back; upper and lower modules. Each of them consists of a parallel kinematics chain with a glass pipette, of 1mm diameter and 3 to 10cm length, tapered to a very sharp end as an end effector. The micro-manipulator hand motion mechanism is driven by three piezo-electric actuated prismatic joints in each of the three legs of the parallel kinematics chain. Each leg of the kinematics chain has the structure of Prismatic-Revolute-Spherical (PRS) joint structure. As the length of the glass pipette end effector is decreased, the resolution and accuracy of the micro-manipulator hand is increased but the effective workspace is decreased. Therefore, the proposed two-fingered micro-manipulator hand consists of two 3-DOF PRS parallel mechanism modules connected in series in a mirror image style for enlarging the effective workspace of end effector and ease of fabrication process. In this thesis, the development process is divided into three main phases; the analysis and mathematical modeling phase, the optimization and design phase, and the realization and implementation phase.-In analysis and mathematical modeling phase, a novel solution of the inverse kinematics problem (IKP) for a given mobile plate center position of a 3-DOF RPS iv parallel mechanism is derived and applied with proper modification to the case of 3-DOF PRS structure of the proposed mechanism. The solution is given in closed form simple equations. The new solution proves that there are eight mathematically accepted solutions with only four solutions that are physically accepted. The IKP for a given end effector position and the forward kinematics problem (FKP) of 3-DOF PRS parallel mechanism are also solved numerically based on the new IKP solution. Then, this solution is extended to …