Tag: Arrow AFM cantilever

Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM

Composite carbon nanofibres (CNFs) are highly interesting materials which are usable in a wide array of applications e.g. electrode materials for biosensors, lithium ion batteries, fuel cells and supercapacitors.*

In their paper “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM” Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann and Thomas Mayer-Gall present a study on the electrical properties of composite carbon nanofibres (CNFs) using current-sensitive atomic force microscopy (CS-AFM).*

This technique makes it possible to explore the electrical properties of single fibers and hence derive relationships between the structural features and the electrical properties.
NanoWorld AFM probes with conductive PtIr5 coated silicon tips (force constant 2.8 N m−1, length 240 μm, mean width 35 μm and a thickness of 3 μm, and tip height 10–15 μm) Arrow-EFM were used.*

The results presented in the paper show that the composite CNFs have a higher electrical conductivity than the neat CNFs and both the average diameter of the fibers and the electrical conductivity increase with an increasing AgNP content.*

Fig. 8 from “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM “ by Wael Ali et al.: CS-AFM analysis of CNFs processed from PAN nanofibres electrospun with different concentrations. Images show the friction and current after both stabilisation (a) and carbonisation (b) processes. The applied bias voltage was +0.15 V. The scan area was 5 × 5 μm2 with a scale bar of 1 μm.

Fig. 8 from “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM “ by Wael Ali et al.: CS-AFM analysis of CNFs processed from PAN nanofibres electrospun with different concentrations. Images show the friction and current after both stabilisation (a) and carbonisation (b) processes. The applied bias voltage was +0.15 V. The scan area was 5 × 5 μm2 with a scale bar of 1 μm.

*Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann, Thomas Mayer-Gall
Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM
RSC Adv., 2019, 9, 4553-4562
DOI: 10.1039/C8RA04594A

Please follow this external link to the full article: https://pubs.rsc.org/en/content/articlehtml/2019/ra/c8ra04594a

Open Access: The article “Electrical conductivity of silver nanoparticle doped carbon nanofibres measured by CS-AFM” by Wael Ali, Valbone Shabani, Matthias Linke, Sezin Sayin, Beate Gebert, Sedakat Altinpinar, Marcus Hildebrandt, Jochen S. Gutmann and Thomas Mayer-Gall is licensed under a Creative Commons Attribution 3.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. To view a copy of this license, visit https://creativecommons.org/licenses/by/3.0/.

Piezoelectricity of green carp scales

Today is Children’s Day in Japan and many mulit-colored carp-shaped koinobori streamers will flutter in the wind.

So it is the perfect day to share the publication “Piezoelectricity of green carp scales” by Y. Jiang et al. with you.

Piezoelectricity takes part in multiple important functions and processes in biomaterials often vital to the survival of organisms. In their publication , “Piezoelectricity of green carp scales” Y. Jiang et al. investigate the piezoelectric properties of fish scales of green carp by directly examining their morphology at nanometer levels. From the clear distinctions between the composition of the inner and outer surfaces of the scales that could be found, the authors identified the piezoelectricity to originate from the presence of hydroxyapatite which only exists on the surface of the fish scales.*

koinobori - carp streamers on children's day in Matsumoto Japan
koinobori – carp streamers in Matsumoto Japan

These findings reveal a different mechanism of how green carp are sensitive to their surroundings and should be helpful to studies related to the electromechanical properties of marine life and the development of bio-inspired materials. As easily accessible natural polymers, fish scales can be employed as highly sensitive piezoelectric materials in high sensitive and high speed devices as well as be exploited for invasive diagnostics and other biomedical implications.*

For the harmonic responses of both 1st order and 2nd order described in this publication, NanoWorld Arrow-CONTPt AFM probes were used.

FIG. 6 from “Piezoelectricity of green carp scales “ by H. Y. Jiang et al.: First and second harmonic responses of (a) domain I and (b) domain IV. The straight line fitting for the amplitude of first harmonic response of (c) domain I and (d) domain IV by applying a series of bias. NanoWorld Arrow-CONTPt AFM probes were used.
FIG. 6 from “Piezoelectricity of green carp scales “ by H. Y. Jiang et al.: First and second harmonic responses of (a) domain I and (b) domain IV. The straight line fitting for the amplitude of first harmonic response of (c) domain I and (d) domain IV by applying a series of bias.

*Y. Jiang, F. Yen, C. W. Huang, R. B. Mei, and L. Chen
Piezoelectricity of green carp scales
AIP Advances 7, 045215 (2017)
DOI: https://doi.org/10.1063/1.4979503

Please follow this external link to access the full article: https://aip.scitation.org/doi/full/10.1063/1.4979503

Open Access The article “Piezoelectricity of green carp scales” by Y. Jiang, F. Yen, C. W. Huang, R. B. Mei and L. Chen is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.

Adhesion strategies of Dictyostelium discoideum – a force spectroscopy study

“Motile cells require reversible adhesion to solid surfaces to accomplish force transmission upon locomotion. In contrast to mammalian cells, Dictyostelium discoideum ( a soil dwelling amoeba) cells do not express integrins forming focal adhesions but are believed to rely on more generic interaction forces that guarantee a larger flexibility; even the ability to swim has been described for Dictyostelium discoideum (D.d.).”*

In order to understand the origin of D.d. adhesion, Nadine Kamprad, Hannes Witt, Marcel Schröder, Christian Titus Kreis, Oliver Bäumchen, Andreas Janshoff and Marco Tarantola  describe in their publication “Adhesion strategies of Dictyostelium discoideum – a force spectroscopy study”* how they realized and modified a variety of conditions for the amoeba comprising the absence and presence of the specific adhesion protein Substrate Adhesion A (sadA), glycolytic degradation, ionic strength, surface hydrophobicity and strength of van der Waals interactions by generating tailored model substrates. By employing AFM-based single cell force spectroscopy (using NanoWorld Arrow-TL2 tipless cantilevers) they could show that experimental force curves upon retraction exhibit two regimes described in detail in the article cited above. The study describes a versatile mechanism that allows the cells to adhere to a large variety of natural surfaces under various conditions.

Fig. 2 A from "Adhesion strategies of Dictyostelium discoideum – a force spectroscopy study": Cell parametrization: β, angle between the normal on the cell membrane and the cell axis; R1, contact radius between the cell and substrate; R0, equatorial cell radius; R2, contact radius between the cell and cantilever, ϕ1 contact angle towards the substrate; ϕ2, contact angle between the cell and cantilever, in the background is a section of the confocal image in B. B: morphology of the carA-1-GFP labelled D.d. cell attached to the cantilever subjected to a pulling force of 0.2 nN. NanoWorld Arrow-TL2 tipless cantilevers were used.
Fig. 2 A from “Adhesion strategies of Dictyostelium discoideum – a force spectroscopy study” by N. Kamprad et al.: Cell parametrization: β, angle between the normal on the cell membrane and the cell axis; R1, contact radius between the cell and substrate; R0, equatorial cell radius; R2, contact radius between the cell and cantilever, ϕ1 contact angle towards the substrate; ϕ2, contact angle between the cell and cantilever, in the background is a section of the confocal image in B. B: morphology of the carA-1-GFP labelled D.d. cell attached to the cantilever subjected to a pulling force of 0.2 nN.

*Nadine Kamprad, Hannes Witt, Marcel Schröder, Christian Titus Kreis, Oliver Bäumchen, Andreas Janshoff, Marco Tarantola
Adhesion strategies of Dictyostelium discoideum – a force spectroscopy study
Nanoscale, 2018, 10, 22504-22519
DOI: 10.1039/C8NR07107A

To read the full article follow this external link: https://pubs.rsc.org/en/content/articlehtml/2018/nr/c8nr07107a

Open Access The article “Adhesion strategies of Dictyostelium discoideum – a force spectroscopy study” by Nadine Kamprad, Hannes Witt, Marcel Schröder, Christian Titus Kreis, Oliver Bäumchen, Andreas Janshoff and Marco Tarantola is licensed under a Creative Commons Attribution 3.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/3.0/.