scholarly journals Direct Shape Recovery from Photometric Stereo with Shadows

2013 ◽  
Author(s):  
Roberto Mecca ◽  
Aaron Wetzler ◽  
Ron Kimmel ◽  
Alfred Marcel Bruckstein
Keyword(s):  
Shape Recovery ◽  
Photometric Stereo

scholarly journals Direct Differential Photometric Stereo Shape Recovery of Diffuse and Specular Surfaces

2016 ◽  
Vol 56 (1) ◽  
pp. 57-76 ◽  
Author(s):  
S. Tozza ◽  
R. Mecca ◽  
M. Duocastella ◽  
A. Del Bue
Keyword(s):  
Shape Recovery ◽  
Photometric Stereo ◽  
Specular Surfaces

A fast LED calibration method under near field lighting based on photometric stereo

2021 ◽  
Vol 147 ◽  
pp. 106749
Author(s):  
Long Ma ◽  
Yuzhe Liu ◽  
Jirui Liu ◽  
Shengwei Guo ◽  
Xin Pei ◽  
...  
Keyword(s):  
Near Field ◽  
Calibration Method ◽  
Photometric Stereo

The effect of latent plasticity on the shape recovery of a shape memory vitrimer

2021 ◽  
Vol 147 ◽  
pp. 110304
Author(s):  
Fengbiao Chen ◽  
Qian Cheng ◽  
Fei Gao ◽  
Jiang Zhong ◽  
Liang Shen ◽  
...  
Keyword(s):  
Shape Memory ◽  
Shape Recovery

scholarly journals Photometric stereo-based high-speed inline battery electrode inspection

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Christian Kapeller ◽  
Ernst Bodenstorfer
Keyword(s):  
Quality Control ◽  
System Architecture ◽  
High Speed ◽  
Shape From Shading ◽  
Production Quality ◽  
Photometric Stereo ◽  
Inspection System ◽  
Coating Materials ◽  
Production Quality Control ◽  
Reconstruction Performance

Abstract Battery technology is a key component in current electric vehicle applications and an important building block for upcoming smart grid technologies. The performance of batteries depends largely on quality control during their production process. Defects introduced in the production of electrodes can lead to degraded performance and, more importantly, to short circuits in final cells, which is highly safety-critical. In this paper, we propose an inspection system architecture that can detect defects, such as missing coating, agglomerates, and pinholes on coated electrodes. Our system is able to acquire valuable production quality control metrics, like surface roughness. By employing photometric stereo techniques, a shape from shading algorithm, our system surmounts difficulties that arise while optically inspecting the black to dark gray battery coating materials. We present in detail the acquisition concept of the proposed system architecture, and analyze its acquisition-, as well as, its surface reconstruction performance in experiments. We carry these out utilizing two different implementations that can operate at a production speed of up to 2000 mm/s at a resolution of 50 µm per pixel. In this work we aim to provide a system architecture that can provide a reliable contribution to ensuring optimal performance of produced battery cells.

scholarly journals Thermally-Induced Shape-Memory Behavior of Degradable Gelatin-Based Networks

2021 ◽  
Vol 22 (11) ◽  
pp. 5892
Author(s):  
Axel T. Neffe ◽  
Candy Löwenberg ◽  
Konstanze K. Julich-Gruner ◽  
Marc Behl ◽  
Andreas Lendlein
Keyword(s):  
Shape Memory ◽  
Shape Memory Effect ◽  
Memory Effect ◽  
Shape Recovery ◽  
Polymer Networks ◽  
Water Soluble ◽  
Compression Tests ◽  
Thermally Induced ◽  
Thermomechanical Process ◽  
Triple Helices

Shape-memory hydrogels (SMH) are multifunctional, actively-moving polymers of interest in biomedicine. In loosely crosslinked polymer networks, gelatin chains may form triple helices, which can act as temporary net points in SMH, depending on the presence of salts. Here, we show programming and initiation of the shape-memory effect of such networks based on a thermomechanical process compatible with the physiological environment. The SMH were synthesized by reaction of glycidylmethacrylated gelatin with oligo(ethylene glycol) (OEG) α,ω-dithiols of varying crosslinker length and amount. Triple helicalization of gelatin chains is shown directly by wide-angle X-ray scattering and indirectly via the mechanical behavior at different temperatures. The ability to form triple helices increased with the molar mass of the crosslinker. Hydrogels had storage moduli of 0.27–23 kPa and Young’s moduli of 215–360 kPa at 4 °C. The hydrogels were hydrolytically degradable, with full degradation to water-soluble products within one week at 37 °C and pH = 7.4. A thermally-induced shape-memory effect is demonstrated in bending as well as in compression tests, in which shape recovery with excellent shape-recovery rates Rr close to 100% were observed. In the future, the material presented here could be applied, e.g., as self-anchoring devices mechanically resembling the extracellular matrix.

Effects of ionic liquid types on the tribological, mechanical, and thermal properties of ionic liquid modified graphene/polyimide shape memory composites

2021 ◽  
pp. 095400832199676
Author(s):  
Yuting Ouyang ◽  
Qiu Zhang ◽  
Xiukun Liu ◽  
Ruan Hong ◽  
Xu Xu ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Ionic Liquid ◽  
Composite Materials ◽  
Shape Memory ◽  
Recovery Rate ◽  
Shape Recovery ◽  
Graphene Nanosheets ◽  
Mechanical And Thermal Properties ◽  
Thermal And Mechanical Properties ◽  
Modified Graphene

Different ionic liquid modified graphene nanosheets (IG) were induced into polyimide (PI) to improve the tribological, thermal, and mechanical properties of shape memory IG/PI composites. The results demonstrated that when using 1-aminoethyl-3-methylimidazole bromide to modify graphene nanosheets (IG-1), the laser-driven shape recovery rate of IG-1/PI composites (IGPI-1) reached 73.02%, which was 49.36% higher than that of pure PI. In addition, the IGPI-1 composite materials reached the maximum shape recovery rate within 15 s. Additionally, under dry sliding, the addition of IG can significantly improve the tribological properties of composite materials. IGPI-1 exhibited the best self-lubricating properties. Compared with pure PI, the friction coefficient (0.19) and wear rate (2.62 × 10–5) mm3/Nm) were reduced by 44.1% and 24.2%, respectively, and the T10% of IGPI-1 increased by 32.2°C. The Tg of IGPI-1 reached 256.5°C, which was 8.4°C higher than that of pure PI. In addition, the tensile strength and modulus of IGPI-1 reached 82.3 MPa and 1.18 GPa, which were significantly increased by 33.6% and 29.8%, respectively, compared with pure PI. We hope that this work will be helpful for the preparation of shape memory materials with excellent tribological, thermal, and mechanical properties.

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