Inertial Slider Research Articles

Characterization and In-Situ Test of Mechanical Properties of MEMS-Based Inertial Delay Slider Mechanism

This paper proposed a method for the in-situ characterization of force applied to the MEMS-based inertial delay slider mechanism. The mechanism mainly includes MEMS W-type spring, sliding gear guide structure, card pin, etc. The force applied on the mechanism, including the spring force, the friction force between the slider and the sliding gear, and the final clamping force could be measured in a single run. According to the measuring result, the calculated spring force and clamping force coincides with the experimental result. In this way, the model for the dynamic process could be validated and modified for an effective description of the operation of the mechanism.

Analysis of vibroexciters working process of the improved efficiency for ice breaking, construction and road machines

In the drives of the working bodies of ice breaking, road, construction and other technological machines the use of asymmetric planetary vibration exciters becomes promising. Where rotation carrier axis of the inertial runner is shifted relative to the treadmill center. Vibro-exciters of this type as a result of the joint action of the centrifugal and Coriolis forces on the inertial slider provide a significant increase in the integral value of the directional driving force. The momentum is proportional to the eccentricity of the carrier and directed towards the specified displacement of the carrier axis. The article presents the original mathematical and graphical dependencies characterizing the workflow of these vibration exciters and confirming their effectiveness.

Compact Scanning Tunneling Microscope with Large Scale Searching Capability for Mmultidisciplinary Applications

We present the design and performance of a home-built scanning tunneling microscope (STM), which is compact (66 mm tall and 25 mm in diameter), yet equipped with a 3D atomic precision piezoelectric motor in which the Z coarse approach relies on a high simplicity friction-type walker (of our own invention) driven by an axially cut piezoelectric tube. The walker is vertically inserted in a piezoelectric scanner tube (PST) with its brim laying flat on the PST end as the inertial slider (driven by the PST) for the XY (sample plane) motion. The STM is designed to be capable of searching rare microscopic targets (defects, dopants, boundaries, nano-devices, etc.) in a macroscopic sample area (square millimeters) under extreme conditions (low temperatures, strong magnetic fields, etc.) in which it fits. It gives good atomic resolution images after scanning a highly oriented pyrolytic graphite sample in air at room temperature.

18/20 T high magnetic field scanning tunneling microscope with fully low voltage operability, high current resolution, and large scale searching ability

We present a home-built 18/20 T high magnetic field scanning tunneling microscope (STM) featuring fully low voltage (lower than ±15 V) operability in low temperatures, large scale searching ability, and 20 fA high current resolution (measured by using a 100 GOhm dummy resistor to replace the tip-sample junction) with a bandwidth of 3.03 kHz. To accomplish low voltage operation which is important in achieving high precision, low noise, and low interference with the strong magnetic field, the coarse approach is implemented with an inertial slider driven by the lateral bending of a piezoelectric scanner tube (PST) whose inner electrode is axially split into two for enhanced bending per volt. The PST can also drive the same sliding piece to inertial slide in the other bending direction (along the sample surface) of the PST, which realizes the large area searching ability. The STM head is housed in a three segment tubular chamber, which is detachable near the STM head for the convenience of sample and tip changes. Atomic resolution images of a graphite sample taken under 17.6 T and 18.0001 T are presented to show its performance.

All low voltage lateral junction scanning tunneling microscope with very high precision and stability

We describe the first lateral junction and fully low voltage scanning tunneling microscope, featuring very high precision, stability, compactness, and image quality (highly oriented pyrolytic graphite atomic resolution images). In its core, the tip and sample each sit on one of two parallel-mounted piezoelectric tube scanners so that the tip-sample gap is regulated along the scanners' pairing direction. The scanner's large lateral deflection provides a large gap regulation range even under low voltages, allowing exclusively using only low voltage (less than +/-15 V) operational amplifiers to precisely implement the coarse (inertial slider) and fine approach, feedback control, and hence the entire electronics. Because the scanners are identical and adjacent, thermal drifts are minimal.

Effect of friction on the performance of inertial slider

Inertial sliders are friction based drives used to position with a resolution of a few hundred of nanometers to over a range of few millimeters. The compactness and simple construction enabled it to be used as a coarse positioner in various Scanning Probe Microscopes (SPM). Even heavy masses has been thought off earlier to use the inertial slider to position precisely, lack of understanding in the dynamical friction behaviour has been the main reason why the inertial sliders potential has not been explored fully in any practical device. In this paper, we have studied the effect of different operating parameters on the step size of the slider.The inertial mass is kept on three sapphire balls, which are attached to shear piezoelectric material. The behaviour of inertial mass was studied for different input waveforms and different surface conditions that come in contact with the sapphire balls. It was observed that under lubricated conditions the step size was reduced.

Multichannels high voltage programmable driver for piezoelectric transducer

A complete design of a compact, high voltage, multichannel programmable waveform generator, using an 8 bit microcontroller, 12 bit digital to analog converter, and high voltage operation amplifier, is presented. The user can generate the waveform by several options: classic waveform, calculator, freehand drawing, and using excel or text file. All the waveform data are stored in a nonvolatile memory of the microcontroller. The generator can work as a stand-alone instrument or conjoined with a personal computer. We used this generator as a controller for piezoelectric inertial slider.

The design and control of a three-dimensional piezoceramic tube scanner with an inertial slider

Inertial sliders are often used to produce coarse relative positioning for scanning probe microscopes. This article describes the design, dynamic analysis, and control of a compact four-segment piezoceramic tube scanner employing an inertial slider. Velocity feedback control, implemented using two-segment piezoelectric sensing, was used to suppress undesired vibrations in the tube, and to improve scanner step uniformity. The control analysis was based on an empirical open-loop identification of the as-built tube behavior, which was also measured using the two-segment sensing technique. A reset integrator friction simulation predicted the overall system performance, and showed good agreement with experimental results.

A highly sensitive atomic force microscope for linear measurements of molecular forces in liquids

We describe a highly improved atomic force microscope for quantitative nanomechanical measurements in liquids. The main feature of this microscope is a modified fiber interferometer mounted on a five axis inertial slider which provides a deflection sensitivity that is significantly better than conventional laser deflection based systems. The measured low noise floor of 572.0fm∕Hz provides excellent cantilever amplitude resolution. This allows us to operate the instrument far below resonance at extremely small cantilever amplitudes of less than 1 Å. Thus linear measurements of nanomechanical properties of liquid systems can be performed. In particular, we present measurements of solvation forces in confined octamethylcyclotetrasiloxane and water with amplitudes smaller than the size of the respective molecules. In general, the development of the instrument is important in the context of quantitative nanomechanical measurements in liquid environments.

Design of a compact scanning tunnelling microscope with a feedback to coarse approach controller for low scan ranges

We describe here the design of a simple and compact scanning tunnelling microscope based on the principle of an inertial slider mechanism. The Z feedback which adjusts the tip–sample gap separation is applied to the coarse movement piezo unlike the conventional method of applying it to the four quadrants of the tip scanning piezo. This method produces better stability in addition to eliminating the requirement of four high voltage amplifiers. Several simple features incorporated in the sample stage improve the stability and reliability considerably.

Compact design of a transmission electron microscope-scanning tunneling microscope holder with three-dimensional coarse motion

A scanning tunneling microscope (STM) with a compact, three-dimensional, inertial slider design is presented. Inertial sliding of the STM tip, in three dimensions, enables coarse motion and scanning using only one piezoelectric tube. Using the same electronics both for scanning and inertial sliding, step lengths of less than 5% of the piezo range were achieved. The compact design, less than 1 cm3 in volume, ensures a low mechanical noise level and enables us to fit the STM into the sample holder of a transmission electron microscope (TEM), while maintaining atomic scale resolution in both STM and TEM imaging.

Instrumentation of STM and AFM combined with transmission electron microscope

A scanning tunneling microscope (STM) combined with a transmission electron microscope (TEM) is a powerful tool for direct investigation of structures, electronic properties, and interactions at the atomic scale. Here, we report on two different designs of such TEM-STM as well as an extension with an atomic force microscope (TEM-AFM). In the first TEM-STM design, a stepper motor, combined with a one-dimensional inertial slider, was used to perform the coarse approach. The advantage of this design was the strong pulling force that enabled notched metallic wires to be broken inside the TEM, which lead to clean sample surfaces. A second design, with a three-dimensional inertial slider, allowed lateral motion inside the TEM, which simplified the adjustment of tip location on the sample. By replacing the STM tip with a standard AFM-cantilever chip, a new combination was demonstrated: TEM-AFM. Here the force was simply measured by direct TEM imaging of the motion of the AFM tip. Some experimental results are included to illustrate the capabilities of TEM-STM and TEM-AFM.

New design of a variable-temperature ultrahigh vacuum scanning tunneling microscope

We present the design of a variable-temperature ultrahigh vacuum (UHV) scanning tunneling microscope which can be operated between 20 and 400 K. The microscope is mounted directly onto the heat exchanger of a He continuous flow cryostat without vibration isolation inside the UHV chamber. The coarse approach is performed with an inertial slider driven by the same piezo tube that is also used for scanning. The performance of the instrument is demonstrated by two different kinds of measurements: First we show topographic images of close packed metal surfaces with atomic resolution. Then, we present results from scanning tunneling spectroscopy measurements on WSe2 under illumination at variable temperatures.

A compact inertial slider STM

A compact, less than , scanning tunnelling microscope (STM) based on a new inertial slider design is presented. The STM is built of two concentric piezoelectric tubes, the inner one for scanning the tip and the outer one for inertial sliding of the sample to and from the tip. The coarse approach is made by inertial sliding of the sample along a plane that is non-perpendicular to the tip, while the sample surface is kept perpendicular to the tip throughout inertial sliding and image acquisitions. The compact design ensures a mechanical noise level of less than 0.1 Å.

A hammer-action micropositioner for scanning probe microscopes

The hammer-action effect produced by the closing of a miniature electromechanical relay was used to propel a rod along a track by the stick–slip inertial slider effect, with step sizes in the range of 30–500 nm and at frequencies up to 75 Hz. The rod was held tightly against the track by spring loaded balls so that the device worked well in any orientation, including vertical motion against gravity. The device was tested as the coarse approach mechanism in a scanning tunneling microscope, at room temperature and liquid nitrogen temperature. The voltage sensitivity actually increased as the temperature was lowered, which is a vast improvement over the piezoelectrically driven micropositioners previously reported in the literature. Further advantages over the piezotranslators are the simple square pulse driving voltage, the much reduced sensitivity to slider surface contaminations, and the improved rigidity. Motion in two- or three-dimensions would be possible by using two or three such translators mounted orthogonally.

A three-axis micropositioner for ultrahigh vacuum use based on the inertial slider principle

We present a three-dimensional micropositioner using the inertial slider principle which is used to position an optical fiber in an atomic force microscope. It uses only two moving parts as the sideways and vertical motions are realized by either moving a cylinder along its axis or rotating it around its axis and translating the rotation into an approximately vertical motion. The device operates reliably in a baked ultrahigh vacuum system, allows positioning with sub-μm accuracy, and has a forward range of 11.3 mm, a sideways range of 5 mm, and a vertical range of approximately 5 mm. The measured speeds without extra load fall in the range between 1.6 and 3.3 mm/min, in good agreement with the amplitude and curve shape of the applied drive signal. The minimal step size allowing consistent motion is below 25 nm.

A bimorph-driven inertial micropositioner for scanning tunnelling microscopy

A bimorph-based inertial linear slider motor, suitable for the coarse approach of the scanning tunnelling microscope tip to the sample, is described. It is best suited for moving micropositioning structures of low height such as bimorph parallelograms, in the z direction, but also for sample stages carrying small samples. It is operated either by trains of voltage pulses of asymmetric shapes, produced by a digital-to-analogue converter, or, since it can also be moved by suitable combinations of binary ones and zeros, simply by switching between two voltage levels. The second case resulted in the most efficient horizontal movement, but it was less successful in moving against gravity.

A scanning tunnelling microscope with a piezoelectric-driven inertial slider

Abstract We report on a scanning tunnelling microscope equipped with a piezoelectric inertial slider micropositioner. For any orientation, the proposed device allows an approach down to the tunnelling distance from the tip. The approach process is fully automated by a personal computer that generates the driving signals. Continuous motion at a speed of 5 mm s −1 and single-step advancement down to 50 A are obtained. The microscope, due to its mechanical symmetry and rigidity, can operate with atomic resolution, using a few stage vibration isolation stacks. The instrument can easily be modified to operate as an atomic force microscope with a fibre-optic-interferometer displacement sensor.

Vertical two-dimensional piezoelectric inertial slider for scanning tunneling microscope

To achieve both high stability during scanning tunneling microscopy (STM) measurements at atomic resolution and long-range imaging of nonhomogeneous samples, we have developed a fully 2D vertical inertial nanopositioner which allows tunneling tip displacements in the 0.01–1000 μm range while keeping high-resolution STM conditions. The inertial sliding of the tip is obtained by overriding the static friction criterion between the tip and its support. By controlling the expansion of the piezotubes and the direction of the applied acceleration, one can obtain displacements as small as 100 Å in the vertical direction. The same piezotubes are also used to scan the sample during conventional STM measurements. Increasing the resonance frequency of the scanner above 10 kHz was essential to ensure good operation. The complete device has not altered the mechanical stability of the microscope; it works in air as well as in ultra-high vacuum conditions. Its reliability is demonstrated by the possibility of obtaining STM images of adjacent areas.

A simple self-propelled two-dimensional micropositioner

A quartz tube is propelled horizontally along a quartz track by the stick-slip inertial slider method, activated by the longitudinal mode of a piezoelectric tube mounted inside the quartz tube. Two-dimensional motion is achieved by rotation of the quartz tube, activated by the bending mode of the piezo. With a sample attached to the quartz tube, the device is an excellent replacement for the electrostatic-clamp type of walker used as the coarse approach mechanism in scanning probe microscopes (SPMs). Alternatively, by attaching the tip (or sample) to the piezo tube, the device can function as a very simple SPM in which the same piezo tube is used for coarse approach and for scanning. The device performs reliably in air and high vacuum, and is ultrahigh vacuum compatible. Step sizes from 10 to 1000 nm, and speeds up to 0.2 mm/s are possible.