Tip Traces Research Articles

Mathematical modelling for compliance-assisted artificial muscle based ornithopter

PurposeThis study aims to discuss the mathematical modelling of a compliance-assisted flapping mechanism and morphable structures for an UAV.Design/methodology/approachA compliance-assisted flapping wing was designed and modelled mathematically, and signals for the corresponding curves were calculated. The actual wing tip trace of a hummingbird was taken, and variables a, b, h and k were calculated from the image. This data was given to the mathematical model for plotting the graph, and the curve was compared with the input curve. The wing frame and mechanism for control surfaces using morphing is modelled along with single pivoted spine for centre of gravity augmentation and flight orientation control.FindingsThe model efficiently approximates the 2D path of the wing using line segments using the muscle and compliance mechanism.Practical implicationsUsing a compliance-assisted flapping mechanism offers practical advantages. It allows us to synchronize the flapping frequency with the input signal frequency, ensuring efficient operation. Additionally, the authors can enhance the torque output by using multiple muscle strands, resulting in a substantial increase in the system’s torque-to-weight ratio. This approach proves to be more favourable when compared to conventional methods involving motors or servos, ultimately offering a more efficient and robust solution for practical application.Social implicationsThis model focuses on creating a flexible and tunable mechanism that can at least trace four types of wing traces from the same design, for shifting from one mode of flight to another.Originality/valueConventional ornithopter flapping mechanisms are gear or servo driven and cannot trace a wing tip, but some can trace complicated curves, but only one at a time. This model can trace multiple curves using the same hardware, allowing the user to program the curve based on their needs or bird. The authors may vary the shape of the wing tip trace to switch between forward flight, hovering, backward flying, etc., which is not conceivable with any traditional flapping mechanism.

Handwriting-Assistant

Pen-based handwriting has become one of the major human-computer interaction methods. Traditional approaches either require writing on the specific supporting device like the touch screen, or limit the way of using the pen to pure rotation or translation. In this paper, we propose Handwriting-Assistant, to capture the free handwriting of ordinary pens on regular planes with mm-level accuracy. By attaching the inertial measurement unit (IMU) to the pen tail, we can infer the handwriting on the notebook, blackboard or other planes. Particularly, we build a generalized writing model to correlate the rotation and translation of IMU with the tip displacement comprehensively, thereby we can infer the tip trace accurately. Further, to display the effective handwriting during the continuous writing process, we leverage the principal component analysis (PCA) based method to detect the candidate writing plane, and then exploit the distance variation of each segment relative to the plane to distinguish on-plane strokes. Moreover, our solution can apply to other rigid bodies, enabling smart devices embedded with IMUs to act as handwriting tools. Experiment results show that our approach can capture the handwriting with high accuracy, e.g., the average tracking error is 1.84mm for letters with the size of about 2cmx1cm, and the average character recognition rate of recovered single letters achieves 98.2% accuracy of the ground-truth recorded by touch screen.

Crocodylian swim tracks from the Gates Formation (Albian), British Columbia, Canada: comparisons with Cretaceous crocodylian ichnology in western USA

Numerous crocodylian swim tracks occur in the late Early Cretaceous and earliest Late Cretaceous of western North America, in coastal plain deposits marginal to the Cretaceous interior seaways. New assemblages from the lower Albian Gates Formation, within the Tumbler Ridge UNESCO Global Geopark Quintette site (TRUGG-Q) in British Columbia, Canada, resemble those from Albian-Cenomanian Dakota Sandstone sites in Colorado, Kansas and Utah, and facilitate comparative analysis of how such assemblages are registered and preserved. The Gates Formation track assemblage formed on the southwest margin of the ‘Moosebar Sea’ that filled the foredeep of the Western Canada Foreland Basin in the Early Albian. Northeast-prograding sandy deltas were backed by low-lying and heavily-vegetated coastal plains, inhabited by track-making dinosaurs, birds, and crocodylians. The base of a tidal channel-fill at the TRUGG-Q site preserves crocodylian swim traces indicating progression largely parallel to the channel axis, as also inferred for some USA sites. Swim track lengths can be categorized on a short–long spectrum which reflects swimming behavior, with short, wide toe tip traces indicating firm digging-in of toes (‘punting’ or ‘poling’ behavior), and elongate scrape marks indicating light touch-down (or substrate ‘raking’) by buoyant animals making intermittent contact with a subaqueous substrate. The body lengths size of crocodylian trackmakers can be calculated from rare complete ‘walking’ track footprints or from the widths, not lengths, in the case of ‘swim’ traces. The mean size of the Canadian tracks indicates individuals with body lengths in the range of ~1.0 m, with larger trackmakers up to ~4.0 m more common at the USA sites.

Rapid nanofabrication via UV-assisted selective etching on GaAs without templates

UV-assisted selective etching was proposed to raise the etching rate for rapid fabrication on GaAs without templates. Within the same time, protrusive hillocks stemming from the photochemical etching are obvious higher than that of traditional chemical etching. The hillock height produced by the photochemical etching increases linearly and then gradually decreases with etching time, and the scratch produced by higher load can change into higher hillock after etching. By programming tip traces, various patterns, including pyramidal tips, were fabricated on GaAs surface. This study provides opportunities for fabricating high-quality GaAs-based optical structures and devices with low cost and high efficiency.

Nondestructive nanofabrication on monocrystalline silicon via site-controlled formation and removal of oxide mask

A nondestructively patterned silicon substrate serves as an ideal support for forming high-quality optical structures or devices. A new approach was proposed for fabricating site-controlled structures without destruction on a monocrystalline silicon surface via local anodic oxidation (LAO) and two-step postetching. The nondestruction was demonstrated by conductivity detection with conductive atomic force microscopy (AFM), and an almost perfect crystal lattice was observed from the fabricated hillock by high-resolution transmission electron microscopy (HRTEM). By programming AFM tip traces for LAO processing, site-controlled nondestructive patterns with different layouts can be produced. This approach provides a new route for realizing nondestructive optical substrates.

Fabrication of periodic nanostructures using dynamic plowing lithography with the tip of an atomic force microscope

The fabrication of periodic nanostructures with a fine control of their dimensions is performed on poly(methyl methacrylate) (PMMA) thin films using an atomic force microscope technique called dynamic plowing lithography (DPL). Different scratching directions are investigated first when generating single grooves with DPL. In particular, the depth, the width and the periodicity of the machined grooves as well the height of the pile-up, formed on the side of the grooves, are assessed. It was found that these features are not significantly affected by the scratching direction, except when processing took place in a direction away from the cantilever probe and parallel to its main axis. For a given scratching direction, arrays of regular grooves are then obtained by controlling the feed, i.e. the distance between two machining lines. A scan-scratch tip trace is also used to reduce processing time and tip wear. However, irregular patterns are created when combining two layers oriented at different angles and where each layer defines an array of grooves. Thus, a “combination writing” method was implemented to fabricate arrays of grooves with a well-defined wavelength of 30nm, which was twice the feed value utilized. Checkerboard, diamond-shaped, and hexagonal nanodots were also fabricated. These were obtained by using the combination writing method and by varying the orientation and the number of layers. The density of the nanodots achieved could be as high as 1.9×109 nanodots per mm2.

Manipulations with diamond nanoparticles in SPM: the effect of electric field of the conductive probe tip

The role of the electric field during manipulations with diamond nanoparticles on a silicon substrate by a scanning probe microscope (SPM) tip is studied. It is found that the attractive force appearing in the contact between nanodiamond and an electrically charged tip is sufficient to detach and displace a chosen nanoparticle from initial to goal position under moderate mechanical stresses of the probe to nanoparticle. The problem of the control of the tip motion trajectory during manipulations is solved by visualizing the tip trace of the sample surface. The results obtained will be used for precision positioning of single-photon emitters based on luminescent nanodiamonds in microcavities.

Online Hand Written Character Recognition

Handwriting processing is a domain in great expansion. The interest devoted to this field is not explained only by the exciting challenges involved, but also the huge benefits that a system, designed in the context of a commercial application, could bring Two classes of recognition systems are usually distinguished: online systems for which handwriting data are captured during the writing process, which makes available the information on the ordering of the strokes, and offline systems for which recognition takes place on a static image captured once the writing process is over. The field of personal computing has begun to make a transition from the desktop to handheld devices, thereby requiring input paradigms that are more suited for single hand entry than a keyboard. Online handwriting recognition allows for such input modalities. On-line handwritten scripts are usually dealt with pen tip traces from pen-down to pen-up positions.

Effects of the AFM tip trace on nanobundles formation on the polymer surface

Atomic Force Microscope (AFM) has become a popular experimental tool for the nanotribological studies. Nanobundles formation perpendicular to the scanning direction has been reported as a typical wear mode for the thermoplastics, and such bundle structures are also considered as sinusoidal wave micro-/nanostructures now. In the present study, the AFM tip based nanomechanical machining method is employed to scratch a polymer Polycarbonate (PC) surface for only once with the normal load of several micro-Newtons in order to achieve the perfect regular nanobundle structures. Based on a modified AFM system, effects of different tip traces in the tip scanning mode and in the sample scanning mode on nanobundles formation on the PC surface are studied. The experimental results show that the controlled reciprocal movement of the stage in the sample scanning mode is feasible for perfect nanobundle structures formation. Moreover, effects of the normal load and the feed on bundles formation in the sample scanning mode are analyzed. Experimental results reveal that the feed value directly affects the formed patterns including the bundles and grooves structures. The reciprocal effect of the tip trace is the decisive factor of forming ideal nanobundles. The repeating times on the same area acted by the tip which are larger than twice are necessary to form a perfect nanobundle structure.

Spatial awareness in Natural Orifice Transluminal Endoscopic Surgery (NOTES) navigation

ObjectiveTo characterise navigational patterns in the abdominal cavity associated with different spatial awareness status of the operator during navigation of Natural Orifice Transluminal Endoscopic Surgery (NOTES). It is hypothesised that poor spatial awareness will manifest as erratic navigational patterns and poor performance. Subjects and methodsTen endoscopic novices navigated a defined course in a NOTES phantom (NOSsE) simulating the path of peritoneoscopic examination. Subjects performed the task three times without and once with an additional laparoscopic camera. Electromagnetic tracking was used to trace the tip of the endoscope during the navigation. Metrics of performance included the number of correctly visualised course targets, between targets localisation time and path length, and total completion time. Spatial awareness was explored by means of topological modelling of the navigation trace. Spatial navigation maps were generated from the tip trace footprint, differentiated using the Earth Movers Distance (EMD) and captured in a two dimensional chart where proximity in the projected space reflects similarity of navigation behaviour. Groups were identified displaying idiosyncratic target to target transitions in endoscopic navigation behaviour. ResultsNo significant differences were found between four sessions in terms of the path length. Time was statistically improved when using supplemental visualisation (p<0.05). Four awareness groups were identified based on the subjects exhibited navigation footprint over the frontal plane, namely: (1) consistent navigation and performance; (2) inconsistent navigation and performance; (3) improvements in navigation and performance despite undifferentiated behavioural signatures; and (4) inconsistent navigation with improvements in performance. ConclusionsTracking the tip of the endoscope permits reconstruction of the navigation path during extraluminal navigation. The spatial location of the tip of the endoscope during navigation was used to unveil the operator's spatial awareness. Navigation routes in this study have been projected onto a 2D scene, related to performance and classified according to exhibited spatial awareness. Our assessment of this relationship suggests that poor spatial awareness is accompanied by erratic manoeuvres, often leading to poor performances, and vice versa. Tracking the location of the tip of the endoscope is an important issue in NOTES, and similarly understanding the spatial awareness of the operator is crucial in terms of the safety in NOTES. This work may have significant implications for training and assessment of new NOTES or minimally invasive surgeons. It may also lead to the new designs of endoscopes for NOTES.

Fabrication of large scale nanostructures based on a modified atomic force microscope nanomechanical machining system

The atomic force microscope (AFM) tip-based nanomechanical machining has been demonstrated to be a powerful tool for fabricating complex 2D∕3D nanostructures. But the machining scale is very small, which holds back this technique severely. How to enlarge the machining scale is always a major concern for the researches. In the present study, a modified AFM tip-based nanomechanical machining system is established through combination of a high precision X-Y stage with the moving range of 100 mm × 100 mm and a commercial AFM in order to enlarge the machining scale. It is found that the tracing property of the AFM system is feasible for large scale machining by controlling the constant normal load. Effects of the machining parameters including the machining direction and the tip geometry on the uniform machined depth with a large scale are evaluated. Consequently, a new tip trace and an increasing load scheme are presented to achieve a uniform machined depth. Finally, a polymer nanoline array with the dimensions of 1 mm × 0.7 mm, the line density of 1000 lines/mm and the average machined depth of 150 nm, and a 20 × 20 polymer square holes array with the scale of 380 μm × 380 μm and the average machined depth of 250 nm are machined successfully. The uniform of the machined depths for all the nanostructures is acceptable. Therefore, it is verified that the AFM tip-based nanomechanical machining method can be used to machine millimeter scale nanostructures.

Friction-induced nanofabrication method to produce protrusive nanostructures on quartz.

In this paper, a new friction-induced nanofabrication method is presented to fabricate protrusive nanostructures on quartz surfaces through scratching a diamond tip under given normal loads. The nanostructures, such as nanodots, nanolines, surface mesas and nanowords, can be produced on the target surface by programming the tip traces according to the demanded patterns. The height of these nanostructures increases with the increase of the number of scratching cycles or the normal load. Transmission electron microscope observations indicated that the lattice distortion and dislocations induced by the mechanical interaction may have played a dominating role in the formation of the protrusive nanostructures on quartz surfaces. Further analysis reveals that during scratching, a contact pressure ranged from 0.4Py to Py (Py is the critical yield pressure of quartz) is apt to produce protuberant nanostructures on quartz under the given experimental conditions. Finally, it is of great interest to find that the protrusive nanostructures can be selectively dissolved in 20% KOH solution. Since the nanowords can be easily 'written' by friction-induced fabrication and 'erased' through selective etching on a quartz surface, this friction-induced method opens up new opportunities for future nanofabrication.

Evaluation Process of Digging Performance for Hydraulic Excavator by Bucket Tip Trace

Evaluation Process of Digging Performance for Hydraulic Excavator by Bucket Tip Trace

Fatigue properties of a S45C steel subjected to ultrasonic nanocrystal surface modification

An ultrasonic nanocrystal surface modification (UNSM) technique, at 3 different vibration strike numbers (34,000 times/mm 2, 45,000 times/mm 2, 68,000 times/mm 2) was used to modify the surface structure and properties of S45C. These three process conditions respectively produced 2 μm, 12 μm and 30 μm nanocrystal layers. UNSM technique improves the following mechanical properties: microhardness, surface roughness, and compressive residual stress. Also, fatigue life increased with the vibration strike number. UNSM C3 (with the vibration strike number of 68,000 times/mm 2) has improved the fatigue strength by as much as 33% for S45C. Optical microscope pictures show that cracks usually initiate from intergranular microcracks on the surface and then extend along the tip traces of UNSM which are considered as process defects. A simple math model (tearing adhesive plaster model) has been made to analyze the initiation and growth of cracks. Though most of the cracks initiate at the surface of specimens, surface nanocrystal layers can help to retard crack initiation. In S45C, the efficiency of crack resistance is more than 48%.the vibration strike number

A12 油圧ショベルのバケット軌跡による掘削性能評価(OS3 ロボットのダイナミクスと制御1)

Recently, automatic digging and remote control hydraulic excavator has been often studied from an productivity and safety standpoint. The productivity for the automatic digging algorithm is a moot point. The ultimate goal of this study is to figure out the digging performance by the simulation for the automatic digging process. Authors define the soil volume per the applied energy as productivity in this paper. At first, a miniature test device was developed to simulate the digging by the pre-programmed bucket tip trace. Besides, digging simulation model by two dimensional distinct element methods (2D-DEM) was developed. The simulation is validated by comparing with the digging test results of the miniature. As the result, it is obtained that the time histories of the reaction forces from the soil and the soil volume for several tip traces. Finally, it is quantitatively clarified that the productivity due to the tip trace.

Manipulation ofC60on theSi(001)surface: Experiment and theory

We extend our previous discussion [D. L. Keeling et al., Phys. Rev. Lett. 94, 146104 (2005)] of molecular rolling on reactive surfaces. Experimental results showing long-range quasiperiodic tip responses with periods of two, three, and four lattice constants are presented. In addition, we show systematic change of the repeating wave form which we attribute to a slow variation of the tip-sample junction at an atomic level. Using ab initio simulations, we have reexamined the translation of ${\mathrm{C}}_{60}$ across the surface and confirmed our proposed pivoting mechanism via which the molecule rolls by sequential breaking and forming bonds with the surface. A complex character of the molecular displacement, which is accompanied by a substantial deformation of the molecule and the surface, is revealed by careful analysis of the atomic geometry and the electron density redistribution along the path. A large variety of observed tip traces along the trough are then explained by analyzing in detail all possible transition paths between the known stable adsorption sites. Detailed models for the periodic traces with two and three lattice constants are also suggested based on a modified pivoting mechanism. In addition, we predict and discuss possible along-the-row manipulation paths.

Fabrication of Probe-Microscope Tips Using Carbon Nanotubes and Their Properties

The development of a scanning probe microscope (SPM) has provided us with atomic resolution images even without a special condition of vacuum. Its principle is that a probe tip traces on the sample surface to detect the information. Thus the property of the tip is directly reflected on the SPM images. Since a carbon nanotube was discovered, it has attracted attention as an ideal material for a SPM tip because of its unique structure and shape. In this article, we will describe the development and subjects to be overcome of a microscope, the potential of a nanotube for a SPM tip, how we have applied a nanotube to a SPM tip, and what we have imaged and done using nanotube tips.

Segmentation and reconstruction of on-line handwritten scripts

On-line handwritten scripts consist of sequences of components that are pen tip traces from pen-down to pen-up positions. This paper presents a segmentation and reconstruction procedure which segments components of a script into sequences of static strokes, and then reconstructs the script from these sequences. The segmentation is based on the extrema of curvature and inflection points in individual components. The static strokes are derived from the delta log-normal model of handwriting generation and are used in component representation and reconstruction. The performance of the procedure is measured in terms of root-mean-square reconstruction error and data compression rate.

STM of macromolecules

Beginning in 1982 when the first images were reported, the development of the scanning tunneling microscope (STM) has revolutionized microscopy in the 1980’s. Although the primary applications are for research on metal and semiconductor surfaces, success in imaging a number of biological samples, mounted on a variety of conductive surfaces, have established STM as a valuable emerging technology in biological research.In 1987 we began our biological STM studies using tobacco mosaic virus (TMV), an easily identifiable rod shaped virus, to test the feasibility of using STM on naked biological samples. We deposited TMV by spraying an aqueous solution of the virus onto evaporated or sputter-coated palladium-gold (Pd/Au) films supported on flat mica surfaces. Although TMV could be clearly identified, its observed width was typically 70-100 nm instead of the known diameter of the virus, 18 nm. On evaporated Pd/Au substrates, tip traces revealed structures elevated above the substrate surface suggesting that the virus became coated with Pd/Au allowing normal conduction to occur. On sputter-coated substrates tip traces revealed depressed substructures.

大ストロークＳＴＭ（走査形トンネル顕微鏡）

We have developed the wide range scanning tunneling microscope (STM) to measure surface topography of a diamond turned gold mirror, a gold coated float polished glass surface and so on. Three dimensional positioning of our STM device is achieved not by using a famous piezoelectric tripod, but by monolithic high precision wide ange translation mechanisms, which we call multi-compound parallel spring. One of strong points of this device is that capability of this specially fabricated X-Y stage is to measure over a sample area of 70μm×70μm and is easily cut from a monolith. We have got an information that each diamond tip trace straightness of the turned surface using a high precision air bearing lathe changes noticeably in the portion. This fact shows that we still have to improve not only such manufacturing conditions as tool radius, and the roughness of tool tips but also the surface finish machine environments especially vibrations.