This paper presents the design and testing of a novel flexure-based compliant parallel gripper with compound constant-force mechanism. One uniqueness of the microgripper lies in that it achieves two-degree-of-freedom (2-DOF) independent constant-force parallel grasping operations. In each direction, the grasping is executed along with active and passive constant-force properties. The passive constant-force property eliminates the use of force control while the active constant-force enlarges the grasping range by reducing the required driving force. Besides, the passive constant-force property can protect the grasped object from overloading. The parallel-kinematic flexure mechanism design enables nearly decoupled operations in 2-DOF manipulation. Analytical modeling of the microgripper mechanism is carried out based on pseudo-rigid-body method and elliptic integral approach, which is verified by conducting simulation study with nonlinear finite-element analysis (FEA). Parametric study is conducted to investigate the influence of dominant design variable on the microgripper performance. To demonstrate the performance of the gripper, a prototype is fabricated by 3D printer. Experimental results reveal that the devised microgripper owns a good decoupling performance and constant-force property in parallel grasping operation.

Design and Testing of a Novel 2-DOF Compound Constant-Force Parallel Gripper

https://research.chalmers.se/publication/521473/file/521473_Fulltext.pdf

The influence of single-channel liquid CO2 and MQL delivery on surface integrity in machining of Inconel 718

Micro-coordinate measuring machines (micro-CMMs) for measuring microcomponents require a probe system with a probe tip diameter of several tens to several hundreds of micrometers. Scale effects work for such a small probe tip, i.e., the probe tip tends to stick on the measurement surface via surface adhesion forces. These surface adhesion forces significantly deteriorate probing resolution or repeatability. Therefore, to realize micro-CMMs, many researchers have proposed microprobe systems that use various surface-sensing principles compared with conventional CMM probes. In this review, the surface-sensing principles of microprobe systems were the focus, and the characteristics were reviewed. First, the proposed microprobe systems were summarized, and the probe performance trends were identified. Then, the individual microprobe system with different sensing principles was described to clarify the performance of each sensing principle. By comprehensively summarizing multiple types of probe systems and discussing their characteristics, this study contributed to identifying the performance limitations of the proposed micro-probe system. Accordingly, the future development of micro-CMMs probes is discussed.

/pdf/surface-sensing-principle-of-microprobe-system-for-micro-2s3wnhz9.pdf

Surface-Sensing Principle of Microprobe System for Micro-Scale Coordinate Metrology: A Review

Carbon dioxide (CO2) snow cleaning is a straightforward surface cleaning process in which a stream of small dry ice particles impact and clean a surface via physical (momentum transfer) and solvent interactions. These interactions have been shown to remove particles of all sizes, from visible to nanometer scale, and to remove organic residues as well as reagent grade solvents. The combination of particle removal over a wide range and organic removal makes the CO2 snow cleaning technique unique in its potential. Furthermore, CO2 snow cleaning systems satisfy the increasingly stringent industrial, research, and environmental demands. Carbon dioxide cleaning is fast, gentle, and environmentally safe. Following a short background, the chapter focuses on some of the diverse cleaning applications, including cleaning vacuum systems and components; atomic force microcopy; nanoprobes; substrates for basic surface science related to polymer adhesion and self-assembled monolayers; telescope mirrors; thin film substrates; semiconductors; small parts; and substrates for biological research.

Carbon Dioxide Snow Cleaning Applications

Influence of module on measurement uncertainty of gear tooth profile deviation on gear measuring center

A fully-functional silicon-based microprobe consisting of three identical measuring cells mounted orthogonally has been developed. The microfabricated measuring cells act as miniaturized load cells, each offering a large measuring range and low stiffness in only one direction thanks to a silicon parallelogram structure. The microassembly of three parallelogram structures using interposers results in an isotropic 3D kinematic microprobe. Piezoresistive sensing provides sub-micrometer accuracy. Highly reproducible and reliable manufacturing processes such as anodic bonding were recently introduced to build the measuring cell. In addition to the standard mechanical and electrical characterization of the microprobe, a dynamic characterization was performed. It was demonstrated that the new microprobe can be used in a commercial coordinate measuring machine (CMM) thereby extending its applicability for dimensional measurement of microcomponents.

Stephan Jantzen

Papers

Microprobe with 3D Orthogonal Kinematics for Dimensional Measurement of Industrial Microparts