scholarly journals A mechatronic shape display based on auxetic materials

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Anthony Steed ◽  
Eyal Ofek ◽  
Mike Sinclair ◽  
Mar Gonzalez-Franco
Keyword(s):  
Soft Material ◽  
Prototype Implementation ◽  
Auxetic Materials ◽  
Continuous Surface ◽  
Sharp Edges ◽  
Common Architecture

AbstractShape displays enable people to touch simulated surfaces. A common architecture of such devices uses a mechatronic pin-matrix. Besides their complexity and high cost, these matrix displays suffer from sharp edges due to the discreet representation which reduces their ability to render a large continuous surface when sliding the hand. We propose using an engineered auxetic material actuated by a smaller number of motors. The material bends in multiple directions, feeling smooth and rigid to touch. A prototype implementation uses nine actuators on a 220 mm square section of material. It can display a range of surface curvatures under the palm of a user without aliased edges. In this work we use an auxetic skeleton to provide rigidity on a soft material and demonstrate the potential of this class of surface through user experiments.

scholarly journals Surface Reconstruction from Structured Light Images Using Differentiable Rendering

Sensors ◽  
2021 ◽  
Vol 21 (4) ◽  
pp. 1068
Author(s):  
Janus Nørtoft Jensen ◽  
Morten Hannemose ◽  
J. Andreas Bærentzen ◽  
Jakob Wilm ◽  
Jeppe Revall Frisvad ◽  
...  
Keyword(s):  
Surface Reconstruction ◽  
Point Cloud ◽  
Structured Light ◽  
Reconstruction Algorithms ◽  
Triangle Mesh ◽  
Intermediate Point ◽  
Structured Light Scanning ◽  
Continuous Surface ◽  
One Step ◽  
Sharp Edges

When 3D scanning objects, the objective is usually to obtain a continuous surface. However, most surface scanning methods, such as structured light scanning, yield a point cloud. Obtaining a continuous surface from a point cloud requires a subsequent surface reconstruction step, which is directly affected by any error from the computation of the point cloud. In this work, we propose a one-step approach in which we compute the surface directly from structured light images. Our method minimizes the least-squares error between photographs and renderings of a triangle mesh, where the vertex positions of the mesh are the parameters of the minimization problem. To ensure fast iterations during optimization, we use differentiable rendering, which computes images and gradients in a single pass. We present simulation experiments demonstrating that our method for computing a triangle mesh has several advantages over approaches that rely on an intermediate point cloud. Our method can produce accurate reconstructions when initializing the optimization from a sphere. We also show that our method is good at reconstructing sharp edges and that it is robust with respect to image noise. In addition, our method can improve the output from other reconstruction algorithms if we use these for initialization.

Antithrombin III Binding to Surface Immobilized Heparin and Its Relation to F Xa Inhibition

1987 ◽  
Vol 58 (04) ◽  
pp. 1064-1067 ◽  
Author(s):  
K Kodama ◽  
B Pasche ◽  
P Olsson ◽  
J Swedenborg ◽  
L Adolfsson ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ionic Strength ◽  
Surface Coating ◽  
Antithrombin Iii ◽  
Lower Class ◽  
Biologically Active ◽  
High Affinity ◽  
Heparin Coating ◽  
Continuous Surface ◽  
Approximate Molecular Weight

SummaryThe mode of F Xa inhibition was investigated on a thromboresistant surface with end-point attached partially depoly-merized heparin of an approximate molecular weight of 8000. Affinity chromatography revealed that one fourth of the heparin used in surface coating had high affinity for antithrombin III (AT). The heparin surface adsorbed AT from both human plasma and solutions of purified AT. By increasing the ionic strength in the AT solution the existence of high and low affinity sites could be shown. The uptake of AT was measured and the density of available high and low affinity sites was found to be in the range of 5 HTid 11 pic.omoles/cmf, respectively Thus the estimated density of biologically active high and low ailmity heparm respectively would be 40 and 90 ng/cm2 The heparin coating did not take up or exert F Xa inhibition by itself. With AT adsorbed on both high and low affinity heparin the surface had the capacity to inhibit several consecutive aliquots of F Xa exposed to the surface. When mainly high affinity sites were saturated with AT the inhibition capacity was considerably lower. Tt was demonstrated that the density of AT on both high and low affinity heparin determines the F Xa inhibition capacity whereas the amount of AT on high affinity sites limits the rate of the reaction. This implies that during the inhibition of F Xa there is a continuous surface-diffusion of AT from sites of a lower class to the high affinity sites where the F Xa/AT complex is formed and leaves the surface. The ability of the immobilized heparin to catalyze inhibition of F Xa is likely to be an important component for the thromboresistant properties of a heparin coating with non-compromized AT binding sequences.

CYCLOPS M4

Alloy Digest ◽  
1978 ◽  
Vol 27 (7) ◽  
Keyword(s):  
High Temperature ◽  
Physical Properties ◽  
Abrasion Resistance ◽  
High Speed ◽  
Heat Treating ◽  
Heavy Duty ◽  
Maximum Hardness ◽  
Temperature Performance ◽  
Sharp Edges ◽  
Normal Carbon

Abstract CYCLOPS M4 is a deep-hardening steel that was developed to utilize the excellent abrasion resistance that results from higher-than-normal carbon and vanadium contents in the molybdenum-tungsten family of high-speed steels. It is recommended for heavy-duty cutting operations and for sharp edges for fine cuts. Cyclops M4 should always be used at or near maximum hardness. This datasheet provides information on composition, physical properties, hardness, and elasticity. It also includes information on high temperature performance as well as forming, heat treating, machining, and joining. Filing Code: TS-335. Producer or source: Cyclops Corporation.

Soft Interfaces

2017 ◽  
Keyword(s):  
Soft Matter ◽  
Capillary Forces ◽  
Soft Material ◽  
Interfacial Phenomena ◽  
Adhesive Tape ◽  
Soft Interfaces ◽  
Lecture Notes ◽  
Lecture Courses

Many of the distinctive and useful phenomena of soft matter come from its interaction with interfaces. Examples are the peeling of a strip of adhesive tape or the coating of a surface or the curling of a fibre via capillary forces or the electrically driven ow along a microchannel, or the collapse of a porous sponge. These interfacial phenomena are distinct from the intrinsic behaviour of a soft material like a gel or a microemulsion. Yet many forms of interfacial phenomena can be understood via common principles valid for many forms of soft matter. Our goal in organizing this school was to give students a grasp of these common principles and their many ramifications and possibilities. The school comprised over fifty 90-minute lectures over four weeks in July 2013. Four four-lecture courses by Howard Stone, Michael Cates, David Nelson, and L. Mahadevan served as an anchor for the program. A number of shorter courses and seminars rounded out the school.This volume presents lecture notes prepared by the speakers and submitted for publication after the school. The lectures are grouped under two main themes: Hydrodynamics and interfaces, and Soft matter.

Magneto-rheological abrasive finishing (MAF) of soft material using abrasives

2021 ◽  
Author(s):  
Rohit Rampal ◽  
Tarun Goyal ◽  
Deepam Goyal ◽  
Manoj Mittal ◽  
Rajeev Kumar Dang ◽  
...  
Keyword(s):  
Soft Material ◽  
Abrasive Finishing ◽  
Magneto Rheological
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