scholarly journals Importance of Molecular Friction in a Soft Polymer−Nanotube Nanocomposite

2008 ◽  
Vol 41 (20) ◽  
pp. 7656-7661 ◽  
Author(s):  
Tao Wang ◽  
Alan B. Dalton ◽  
Joseph L. Keddie
Keyword(s):  
Soft Polymer ◽  
Molecular Friction

scholarly journals Soft Jumping Robot Using Soft Morphing and the Yield Point of Magnetic Force

2021 ◽  
Vol 11 (13) ◽  
pp. 5891
Author(s):  
Gang-Hyun Jeon ◽  
Yong-Jai Park
Keyword(s):  
Residual Stress ◽  
Polymer Materials ◽  
Rigid Base ◽  
Release Mechanism ◽  
Transfer Energy ◽  
Deformation Control ◽  
Energy Retention ◽  
Base Jumping ◽  
Jumping Robot ◽  
Soft Polymer

In this paper, soft-morphing, deformation control by fabric structures and soft-jumping mechanisms using magnetic yield points are studied. The durability and adaptability of existing rigid-base jumping mechanisms are improved by a soft-morphing process that employs the residual stress of a polymer. Although rigid body-based jumping mechanisms are used, they are driven by multiple components and complex structures. Therefore, they have drawbacks in terms of shock durability and fatigue accumulation. To improve these problems, soft-jumping mechanisms are designed using soft polymer materials and soft-morphing techniques with excellent shock resistance and environmental adaptability. To this end, a soft jumping mechanism is designed to store energy using the air pressure inside the structure, and the thickness of the polymer layer is adjusted based on the method applied for controlling the polymer freedom and residual stress deformation. The soft jumping mechanism can transfer energy more efficiently and stably using an energy storage and release mechanism and the rounded ankle structure designed using soft morphing. Therefore, the soft morphing and mechanisms of energy retention and release were applied to fabricate a soft robot prototype that can move in the desired direction and jump; the performance experiment was carried out.

Characterization of Piezoelectric Nanofiber Composites Acoustic Emission Sensor for Structure Health Monitoring

2012 ◽  
Author(s):  
Xi Chen ◽  
Yong Shi
Keyword(s):  
Acoustic Emission ◽  
Lead Zirconate Titanate ◽  
High Sensitivity ◽  
Lead Zirconate ◽  
Steel Bar ◽  
Promising Application ◽  
Soft Polymer ◽  
Active Fiber Composites ◽  
The Mathematical Model

A nanoscale active fiber composites (NAFCs) based acoustic emission (AE) sensor with high sensitivity is developed. The lead zirconate titanate (PZT) nanofibers, with the diameter of approximately 80 nm, were electrospun on a silicon substrate. Nanofibers were parallel aligned on the substrate under a controlled electric field. The interdigitated electrodes were deposited on the PZT nanofibers and packaged by spinning a thin soft polymer layer on the top of the sensor. The hysteresis loop shows a typical ferroelectric property of as-spun PZT nanofibers. The mathematical model of the voltage generation when the elastic waves were reaching the sensor was studied. The sensor was tested by mounting on a steel surface and the measured output voltage under the periodic impact of a grounded steel bar was over 35 mV. The small size of the developed PZT NAFCs AE sensor shows a promising application in monitoring the structures by integration into composites.

Electromechanical characterization of magnetic responsive and conductive soft polymer actuators

2020 ◽  
pp. 349-361 ◽  
Author(s):  
A.W. Gan ◽  
Kirthika Senthil Kumar ◽  
Lei Zhang ◽  
Jianyong Ouyang ◽  
Hongliang Ren
Keyword(s):  
Polymer Actuators ◽  
Soft Polymer ◽  
Electromechanical Characterization

Asymmetric Molecular Friction in Supported Phospholipid Bilayers Revealed by NMR Measurements of Lipid Diffusion

Langmuir ◽  
1998 ◽  
Vol 14 (5) ◽  
pp. 982-984 ◽  
Author(s):  
M. Hetzer ◽  
S. Heinz ◽  
S. Grage ◽  
T. M. Bayerl
Keyword(s):  
Phospholipid Bilayers ◽  
Lipid Diffusion ◽  
Molecular Friction

scholarly journals High-Velocity Shear and Soft Friction at the Nanometer Scale

2021 ◽  
Vol 7 ◽  
Author(s):  
Per-Anders Thorén ◽  
Riccardo Borgani ◽  
Daniel Forchheimer ◽  
David B. Haviland
Keyword(s):  
High Speed ◽  
Surface Deformation ◽  
Soft Materials ◽  
Lateral Force ◽  
Velocity Shear ◽  
Polymer Materials ◽  
Amplitude Dependence ◽  
Dynamic Force ◽  
Stick Slip ◽  
Soft Polymer

We study high-speed friction on soft polymer materials by measuring the amplitude dependence of cyclic lateral forces on the atomic force microscope (AFM) tip as it slides on the surface with fixed contact force. The resulting dynamic force quadrature curves separate the elastic and viscous contributions to the lateral force, revealing a transition from stick-slip to free-sliding motion as the velocity increases. We explain force quadratures and describe how they are measured, and we show results for a variety of soft materials. The results differ substantially from the measurements on hard materials, showing hysteresis in the force quadrature curves that we attribute to the finite relaxation time of viscoelastic surface deformation.

scholarly journals Effect of Polymer-Ceramic Fibre Interphase Design on Coupling Factor in Low Fibre Volume Content Piezoelectric Composites

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Tony Lusiola ◽  
Sophie Oberle ◽  
Lovro Gorjan ◽  
Frank Clemens
Keyword(s):  
Epoxy Resin ◽  
Lead Zirconate Titanate ◽  
Electromechanical Coupling ◽  
Electromechanical Coupling Factor ◽  
Polymer Coatings ◽  
Coupling Factor ◽  
Fibre Volume ◽  
Resin Matrix ◽  
Ceramic Fibre ◽  
Soft Polymer

In this work, we investigated different short molecule polymer coatings in piezoelectric ceramic-polymer composites with low fibre volume contents. Modifying the interphase between the piezoelectric PZT (lead zirconate titanate) fibre and the epoxy matrix thus enhances the electromechanical coupling factor for 1–3 ultrasound transducers with low fibre contents. It is known that the electromechanical coupling factor can be increased by precoating a ceramic fibre with a soft interlayer polymer [1-1-3]. In this paper, we investigate the so-called 1-1-1-3 composites composed of a ferroelectric ceramic fibre (core), a soft polymer layer (e.g., fatty acids, amides, waxes, or oils), an epoxy resin shell, and an epoxy resin matrix. Some soft polymer layers allowed the free movement of the ferroelectric fibres reducing blocking or clamping by the inactive polymeric matrix, resulting in higher electromechanical coupling factors (kt) for composites with low fibre volume contents. Using an oil-based interlayer, the dielectric constant can be significantly increased. The lowest fibre push-out stress could be achieved with the paraffin interlayer; however, no correlation with the coupling factor could be observed.

Accessibility of Densely Localized DNA on Soft Polymer Nanoparticles

Langmuir ◽  
2018 ◽  
Vol 34 (49) ◽  
pp. 14731-14737 ◽  
Author(s):  
Munira F. Fouz ◽  
Sourav K. Dey ◽  
Kosuke Mukumoto ◽  
Krzysztof Matyjaszewski ◽  
Bruce A. Armitage ◽  
...  
Keyword(s):  
Polymer Nanoparticles ◽  
Soft Polymer

scholarly journals Finite Element Analysis of the Nanomechanics of Hard Coatings on a Soft Polymer Substrate by a Spherical Indenter

2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Chunlai Tian ◽  
Pengfei Duan
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Young’S Modulus ◽  
Young's Modulus ◽  
Viscoelastic Model ◽  
Coating System ◽  
Element Analysis ◽  
Soft Polymer ◽  
Indentation Response

Composite has been widely used in various fields due to its advanced performance. To reveal the relation between the mechanical properties of the composite and that of each individual component, finite element analysis (FEA) has usually been adopted. In this study, in order to predict the mechanical properties of hard coating on a soft polymer, the response of this coating system during nanoindentation was modelled. Various models, such as a viscoelastic model and fitting model, were adopted to analyse the indentation response of this coating system. By varying the substrate properties (i.e., Young’s modulus, viscoelasticity, and Poisson’s ratio), Young’s modulus, energy loss, and the viscoelastic model of the coating system were analysed, and how the mechanical properties of the substrate will affect the indentation response of the coating system was discussed.

Sign in / Sign up

Export Citation Format

Share Document