Multi-axis Micro Research Articles

Multiaxis three dimensional (3D) carbon and basalt preforms/cementitious matrix concretes: Experimental study on fiber orientation and placement by panel test

Multiaxis three-dimensional (3D) continuous basalt and carbon fiber/cementitious matrix concretes were developed and their panel properties were experimentally investigated. It was found that the fiber placement and orientation in concrete remarkably affected its load carrying, strength, and energy absorption performance. It was identified that the multiaxis 3D fiber concrete had strain hardening behavior. The strain hardening increased the energy absorbing capacity of the concrete. Four directional basalt and carbon structures exhibited slightly better energy absorption compared to the biaxial and uniaxial structures due to the multiaxis fiber orientation. Failed fiber concretes had local matrix breakages, matrix-filament bundle debonding in each yarn set, yarn bridging due to tensile strengthening, outer filament tensile pull-out and stick–slip phenomena between filaments in the yarn, and a cementitious matrix. This led to the in-plane angularly radial aligned multiaxis micro cracks, which were probably controlled by the multiaxis 3D fiber architecture, and they were considered damage tolerant materials.

Micro electrical discharge machining of small hole in TC4 alloy

Aiming at machining deeply small holes in TC4 alloy, a series of experiments were carried out on a self-developed multi-axis micro electrical discharge machining (micro-EDM) machine tool. To improve machining efficiency and decrease relative wear of electrode in machining deeply small hole in TC4 alloy, many factors in micro-EDM, such as polarity, electrical parameters and supplying ways of working fluid were studied. Experimental results show that positive polarity machining is far superior to negative polarity machining; it is more optimal when open-circuit voltage, pulse width and pulse interval are 130 V, 5 μs and 15 μs respectively on the self developed multi-axis micro-EDM machine tool; when flushing method is applied in micro-EDM, the machining efficiency is higher and relative wear of electrode is smaller.

Design and calibration of a MEMS sensor for measuring the force and torque acting on a magnetic microrobot

This paper presents the design, fabrication and calibration of a multi-axis micro force–torque sensor. The sensor and its readout electronics are specifically designed to simultaneously measure two force components and one torque component. The load is measured by capacitive comb drives which provide high sensitivity. The sensor is applied to measure micro-Newton level forces and nano-Newton-meter level torques on a magnetically actuated microrobot. This microrobot is assembled from microfabricated nickel parts and is designed for directed drug delivery inside the human body. The precise knowledge of the forces and torques will help design magnetic position controllers as well as understand the magnetic properties of the electroplated microparts.

A novel parallel-kinematics mechanisms for integrated, multi-axis nanopositioning

Abstract Multi-axis micro and nanopositioning systems are increasingly used in much of the metrology and process equipment related to the field of nanotechnology. This, the first of a two-part series of papers on a novel piezo-driven, parallel-kinematics XYZ nanopositioning (PKXYZNP) stage, concentrates on the development of a viable scheme to achieve pure spatial translation. First, the mechanism is shown to admit closed-form solutions to both; the forward and reverse kinematic problems. The Jacobian and the dynamics of the system indicate that the mechanical structure produces a relatively large work volume, and is capable of high bandwidth and uniform performance across it. The fabrication of the system is described along with some basic testing of its Jacobian and its modal frequencies. Using capacitive gages, the stage is capable of about 85 μm of motion along each axis with a resolution of about 2–4 nm. The controls, testing and performance are discussed in detail in the companion paper [Dong J, Yao Q, Ferreira PM. A novel parallel-kinematics mechanism for integrated, multi-axis nanopositioning. Part 2. Dynamics, control and performance analysis. Precis Eng].