In this letter we demonstrate a pneumatic bending actuator for upper-limb assistive wearable robots which uses thin McKibben muscles in combination with flexure strip. The features both active soft actuation and passive gravity support, terms of force transmission bridges the gap between classic rigid type actuators emerging technologies. Its strip leverages high-force low-displacement properties towards large rotational range motion reduces localized forces at attachments. We explain...

Large-stroke flexure mechanisms inherently lose stiffness in supporting directions when deflected. A systematic approach to synthesize such hinges is currently lacking. In this paper, a new building block-based spatial topology synthesis method presented for optimizing large-stroke hinges. This consists of layout variation strategy based on block combined with shape optimization obtain the optimal design tuned specific application. derivative-free adapted include multiple system boundaries...

Flexure hinges inherently lose stiffness in supporting directions when deflected. In this paper a method is presented for optimizing the geometry of flexure hinges, which aims at maximizing stiffnesses. addition, new ∞-flexure hinge design presented. The considered are subjected to load and deflected an angle up ±20 deg. measure performance defined by first unwanted natural frequency, closely related During optimization, constraints applied actuation moment maximum occurring stress....

Various systems exist for CT-guided needle placement in the thorax and abdomen, but widespread adoption is lacking. The goal of this work to develop a system precise with design focus on clinical acceptability, applicability usability.A was outlined incorporating guide mechanism remote centre motion, manually placeable around patient at desired entry point lockable by push-button CT table. System are scanned system-to-CT registration target specification. automatically aimed target, manual...

In this paper, we propose a flexure spring based gravity compensation device which provides assistance to lift the forearm. Three different designs are obtained and evaluated. The synthesis method obtain these is explained in detail an experimental evaluation validates desired balancing properties. It found that comparison with constant thickness, variable thickness distribution along leads drastic reduction of its width, amounts 81 % presented case, offers energy weight ratio 94 higher....

This work presents a MEMS displacement sensor based on the conductive heat transfer of resistively heated silicon structure towards an actuated stage parallel to structure. differential can be easily incorporated into silicon-on-insulator-based process, and fabricated within same mask as electrostatic actuators flexure-based stages. We discuss lumped capacitance model optimize sensitivity function doping concentration, operating temperature, heater length width. demonstrate various designs....

The stroke of a microelectromechanical systems (MEMS) stage suspended by flexure mechanism and actuated electrostatic comb-drives is limited pull-in. A method to analyze the stability optimize with respect footprint mechanisms presented. Four for large are investigated; standard folded flexure, slaved tilted Watt flexure. Given certain load force, flexures optimized have minimum wafer footprint. From these optimizations it concluded that best relatively small strokes (up ±40 μm) larger...

Abstract-This paper presents the design, modeling, and fabrication of a planar three-degrees-of-freedom parallel kinematic manipulator, fabricated with simple two-mask process in conventional highly doped single-crystalline silicon (SCS) wafers (100). The manipulator's purpose is to provide accurate stable positioning small sample (10 × 20 0.2 μm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> ), e.g., within transmission electron...

This paper describes the mechatronic design of a humanoid neck. To research human machine interaction, head and neck combination should be able to approach behavior as much possible. We present novel concept that is both fast, has long range motion in 4 degrees freedom (DOFs). enables track fast objects, suitable for mimicking expressions. The features differential drive lower 2 DOFs resulting low moving mass ability use strong actuators. performance been optimized by minimizing backlash...

A flexure strip has constraint characteristics, such as stiffness properties and error motions, that govern its performance a basic constituent of mechanisms. This paper presents new modeling approach for obtaining insight into the deformation characteristics general three-dimensional strips exhibit bending, shear, torsion deformation. The is based on use discretized version finite (i.e., nonlinear) strain spatial beam formulation extracting analytical expressions describe in parametric...

This paper describes the mechatronic design of Twente humanoid head, which has been realized in purpose having a research platform for human-machine interaction. The features fast, four degree freedom neck, with long range motion, and vision system three degrees freedom, mimicking eyes. To achieve fast target tracking, two neck are combined differential drive, resulting low moving mass possibility to use powerful actuators. performance optimized by minimizing backlash mechanisms, using...

Flexure based stages are particularly important for vacuum applications because they combine low hysteresis, no wear and contamination with a high supporting stiffness. However, flexure hinges inherently lose stiffness in directions when deflected. Therefore the workspace to footprint ratio is limited. In this article we present design modeling of two degrees freedom cross stage that combines large vibration mode frequencies. Because mechanism an assembly optimized components, designed...

Precise mass flow control is an essential requirement for novel, small-scale fluidic systems. However, a small-volume, low-leakage proportional valve minute fluid flows has not yet been designed or manufactured. A survey therefore made of the primary design considerations micromachined, valve. Performance requirements are identified based on various applications. Valve operating principles and actuation schemes presented in literature evaluated with respect to functionality technological...

A micro-actuator for precision alignment, using laser forming of a tube, is presented. Such an actuator can be used to align components after assembly. The positioning optical fiber with respect waveguide chip as test case, where submicron lateral alignment accuracy required. stainless steel tube outer diameter 635 μm was simple and compact actuator, the mounted concentrically in tube. An experimental setup has been developed measure displacement real time resolution better than 0.1 μm. In...

The sheet flexure is commonly used to provide support stiffness in mechanisms for precision applications. While the often analyzed a simplified form, e.g. by assuming planar deformation or linearized stiffness, practice spatial and sufficiently large that nonlinear effects due geometric are significant. This paper presents compact analytical model characteristics of spatially deforming flexures under general 3-D load conditions at moderate deformations. provides closed-form expressions mixed...