88 research outputs found
Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores
When two macroscopic objects touch, the real contact typically consists of multiple surface asperities that are deformed under the pressure that holds the objects together. Application of a shear force makes the objects slide along each other, breaking the initial contacts. To investigate how the microscopic shear force at the asperity level evolves during the transition from static to dynamic friction, we apply a fluorogenic mechanophore to visualize and quantify the local interfacial shear force. When a contact is broken, the shear force is released and the molecules return to their dark state, allowing us to dynamically observe the evolution of the shear force at the sliding contacts. We find that the macroscopic coefficient of friction describes the microscopic friction well, and that slip propagates from the edge toward the center of the macroscopic contact area before sliding occurs. This allows for a local understanding of how surfaces start to slide
cDNA microarray analysis of the effect of cantharidin on DNA damage, cell cycle and apoptosis-associated gene expression in NCI-H460 human lung cancer cells in vitro
Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores
When two macroscopic objects touch, the real contact
typically
consists of multiple surface asperities that are deformed under the
pressure that holds the objects together. Application of a shear force
makes the objects slide along each other, breaking the initial contacts.
To investigate how the microscopic shear force at the asperity level
evolves during the transition from static to dynamic friction, we
apply a fluorogenic mechanophore to visualize and quantify the local
interfacial shear force. When a contact is broken, the shear force
is released and the molecules return to their dark state, allowing
us to dynamically observe the evolution of the shear force at the
sliding contacts. We find that the macroscopic coefficient of friction
describes the microscopic friction well, and that slip propagates
from the edge toward the center of the macroscopic contact area before
sliding occurs. This allows for a local understanding of how surfaces
start to slide
Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores
When two macroscopic objects touch, the real contact
typically
consists of multiple surface asperities that are deformed under the
pressure that holds the objects together. Application of a shear force
makes the objects slide along each other, breaking the initial contacts.
To investigate how the microscopic shear force at the asperity level
evolves during the transition from static to dynamic friction, we
apply a fluorogenic mechanophore to visualize and quantify the local
interfacial shear force. When a contact is broken, the shear force
is released and the molecules return to their dark state, allowing
us to dynamically observe the evolution of the shear force at the
sliding contacts. We find that the macroscopic coefficient of friction
describes the microscopic friction well, and that slip propagates
from the edge toward the center of the macroscopic contact area before
sliding occurs. This allows for a local understanding of how surfaces
start to slide
Datafiles: Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores
The raw data and the Matlab code for the publication :
Chao-Chun Hsu, Feng-Chun Hsia, Bart Weber, Matthijn B. de Rooij, Daniel Bonn, and Albert M. Brouwer,
Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores,
The Journal of Physical Chemistry Letters 2022 13 (38), 8840-8844
10.1021/acs.jpclett.2c02010
Citation: DOI: 10.1021/acs.jpclett.2c02010
Please find more details in the Readme file at each archive file. </p
Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores
When two macroscopic objects touch, the real contact
typically
consists of multiple surface asperities that are deformed under the
pressure that holds the objects together. Application of a shear force
makes the objects slide along each other, breaking the initial contacts.
To investigate how the microscopic shear force at the asperity level
evolves during the transition from static to dynamic friction, we
apply a fluorogenic mechanophore to visualize and quantify the local
interfacial shear force. When a contact is broken, the shear force
is released and the molecules return to their dark state, allowing
us to dynamically observe the evolution of the shear force at the
sliding contacts. We find that the macroscopic coefficient of friction
describes the microscopic friction well, and that slip propagates
from the edge toward the center of the macroscopic contact area before
sliding occurs. This allows for a local understanding of how surfaces
start to slide
Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores
When two macroscopic objects touch, the real contact
typically
consists of multiple surface asperities that are deformed under the
pressure that holds the objects together. Application of a shear force
makes the objects slide along each other, breaking the initial contacts.
To investigate how the microscopic shear force at the asperity level
evolves during the transition from static to dynamic friction, we
apply a fluorogenic mechanophore to visualize and quantify the local
interfacial shear force. When a contact is broken, the shear force
is released and the molecules return to their dark state, allowing
us to dynamically observe the evolution of the shear force at the
sliding contacts. We find that the macroscopic coefficient of friction
describes the microscopic friction well, and that slip propagates
from the edge toward the center of the macroscopic contact area before
sliding occurs. This allows for a local understanding of how surfaces
start to slide
Datafiles: Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores
The raw data and the Matlab code for the publication :
Chao-Chun Hsu, Feng-Chun Hsia, Bart Weber, Matthijn B. de Rooij, Daniel Bonn, and Albert M. Brouwer,
Local Shearing Force Measurement during Frictional Sliding Using Fluorogenic Mechanophores,
The Journal of Physical Chemistry Letters 2022 13 (38), 8840-8844
10.1021/acs.jpclett.2c02010
Citation: DOI: 10.1021/acs.jpclett.2c02010
Please find more details in the Readme file at each archive file. </p
Realization and direct observation of five normal and parametric modes in silicon nanowire resonators by in situ transmission electron microscopy
Mechanical resonators have wide applications in sensing bio-chemical substances, and provide an accurate method to measure the intrinsic elastic properties of oscillating materials. A high resonance order with high response frequency and a small resonator mass are critical for enhancing the sensitivity and precision. Here, we report on the realization and direct observation of high-order and high-frequency silicon nanowire (Si NW) resonators. By using an oscillating electric-field for inducing a mechanical resonance of single-crystalline Si NWs inside a transmission electron microscope (TEM), we observed resonance up to the 5th order, for both normal and parametric modes at ∼100 MHz frequencies. The precision of the resonant frequency was enhanced, as the deviation reduced from 3.14% at the 1st order to 0.25% at the 5th order, correlating with the increase of energy dissipation. The elastic modulus of Si NWs was measured to be ∼169 GPa in the [110] direction, and size scaling effects were found to be absent down to the ∼20 nm level
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