Design principles for six degrees-of-freedom MEMS-based precision manipulators

In the future, the precision manipulation of small objects will become more and more important for appliances such as data storage, micro assembly, sample manipulation in microscopes, cell manipulation, and manipulation of beam paths by micro mirrors. At the same time, there is a drive towards miniaturized systems.\ud Therefore, Micro ElectroMechanical Systems (MEMS), a fabrication technique enabling micron sized features, has been researched for precision manipulation. MEMS devices comprise micro sensors, actuators, mechanisms, optics and fluidic systems. They have the ability to integrate several functions in a small package. MEMS can be commercially attractive by providing cost reduction or enabling new functionality with respect to macro systems. Combining design principles, a mature design philosophy for creating precision machines, and MEMS fabrication, a\ud technology for miniaturization, could lead to micro systems with deterministic behavior and accurate positioning capability. However, in MEMS design trade-offs\ud need to be made between fabrication complexity and design principle requirements.\ud Therefore, the goal of this research has been twofold:\ud 1. Design and manufacture a 6 Degrees-of-Freedom (DOFs) MEMS-based manipulator with nanometer resolution positioning.\ud 2. Derive principle solutions for the synthesis of exact kinematic constraint design and MEMS fabrication technology for multi DOFs precision manipulation in the\ud micro domain

Novel Dexterous Robotic Finger Concept with Controlled Stiffness

This paper introduces a novel robotic finger concept for variable impedance grasping in unstructured tasks. The novel robotic finger combines three key features: minimal actuation, variable mechanical compliance and full manipulability. This combination of features allows for a minimal component design, while reducing control complexity and still providing required dexterity and grasping capabilities. The conceptual properties (such as variable compliance) are studied in a port-Hamiltonian framework

6-DoFs MEMS-based precision manipulators

Combining Design Principles, a mature design philosophy for creating precision machines, and MEMS fabrication, a technology for miniaturization, could lead to micro systems with deterministic behavior and accurate positioning capability. However, in MEMS design tradeoffs need to be made between fabrication complexity and design principle requirements. Here a micro-mechatronic design of a Stewart Platform, a six Degrees-of-Freedom MEMSbased Precision Manipulator, is presented

Mechatronic design of the Twente humanoid head

This paper describes the mechatronic design of the Twente humanoid head, which has been realized in the purpose of having a research platform for human-machine interaction. The design features a fast, four degree of freedom neck, with long range of motion, and a vision system with three degrees of freedom, mimicking the eyes. To achieve fast target tracking, two degrees of freedom in the neck are combined in a differential drive, resulting in a low moving mass and the possibility to use powerful actuators. The performance of the neck has been optimized by minimizing backlash in the mechanisms, and using gravity compensation. The vision system is based on a saliency algorithm that uses the camera images to determine where the humanoid head should look at, i.e. the focus of attention computed according to biological studies. The motion control algorithm receives, as input, the output of the vision algorithm and controls the humanoid head to focus on and follow the target point. The control architecture exploits the redundancy of the system to show human-like motions while looking at a target. The head has a translucent plastic cover, onto which an internal LED system projects the mouth and the eyebrows, realizing human-like facial expressions

Efficient Collision Detection Method for Flexure Mechanisms Comprising Deflected Leafsprings

When designing and optimizing spatial flexure mechanisms, it is hard to predict collision due to 3D motion and large deformations, which compromises the utilization of spatial freedom. A computationally efficient collision test is desirable to assure that feasible mechanism designs are found when algorithmically optimizing the shape of elastic mechanisms, which are prone to collision. In this paper, a method is presented to test for collision specifically suited for flexure mechanisms by taking advantage of the typical slender aspect ratio and shape of the elastic members. Hereby, an efficient collision test is obtained that allows for the computation of a quantitative value for the severeness of collision. This value can then be used to efficiently converge to collision free solutions without excluding good mechanism designs leading to improved mechanisms, which utilize the maximum spatial design freedom