Atomic Force Microscopy - Science method
Atomic Force Microscopy are aFM is a very high-resolution type of scanning probe microscopy, with demonstrated resolution on the order of fractions of a nanometer, more than 1000 times better than the optical diffraction limit.
Questions related to Atomic Force Microscopy
how d i interpret or determine with the mesure distance the pitchand compare characteristic freature szeand density among three media with statistical data things like total projected area, mean grain areaand mean grain size
Can anyone suggest something to resolve the issue of distorted friction images on the AFM? We tried several things: switching off the system and computer, reconnecting wires, changing tip, scan rate, scan angles, gain values, vibration table, and sample. The scans are taken in contact mode at a very low normal load. The topography images are still better but friction images are just noise. We are using the 5500 Agilent Technologies AFM (pretty old). Thank you.
I wanna study a multiferroic material which is ferroelectric and antiferromagnetic using CASTEP. I need your guidance regarding study of AFM material and also i wanna know how spin polarization box work ?
I'm trying to study HPHT synthetic diamond plates with low (first nm roughness). When i taking 100×100 μm photo by AFM, you can see a lot of flakes/dirt on them.
The question is how can i remove this dirt? I already tryed ultrasonic cleaning in ethanol, but it doesn't remove dirt at all.
What could be the reason for this situation in the AFM image? Is what is marked a DEFECT? and why. This is an image (AFM) for ZnO prepared by Sputtering method with -200 V as bias voltage and after annealing at 450 °C.
Hello all! I would like to know about the force spectroscopy whether a Bruker ScanAsyst system with Nanoscope Analysis user interface can provide single-molecule force measurements data. Any special modules needed to perform the single-molecule force (SMF) measurements ? I am able to get only indentation force curves (Force-distance curves) which might not be the same as SMF curves.
A clarity in the discussion is highly appreciated.
Thanks in advance!
Generally height height correlation function is computed in one dimension along fast scaning axis (x direction). My query is " how to compute hhch in polar coordinates fron afm measurement".
We are using Shimadzu SPM-9700HT AFM in the lab. It uses a 650nm laser for cantilever detection. I want to replace the laser to a longer wavelength to avoid excitation of fluorescent samples. If you have experience of replacing the laser unit, would you please be able to share the experience here?
about type of josephson junction is called step edge ,considering that the created step edge is in micro-nanometer scale, how can you determine the area to be measured in AFM analysis ؟How to determine the border of the covered area from the etched area under the microscope (AFM or SEM)?
Is there a need to mark the back of the sample?
I am a Master's student of Mechanical Engineering at Gwangju Institute of Science and Technology, South Korea. What can be a good thesis topic for mechanical students on AFM research?
I am working on AFM for the last six months. I have gained sufficient knowledge about the components of AFM, and their effect on the speed of AFM.
For my thesis, I want to work on the side of Signal Processing (to improve the resolution of the acquired images), I am more familiar with the control work and if the control doesn't take a long time I will be happy to work on the control side.
I have searched a lot about research trends on AFM and get to know we have two trends
1. High-Speed AFM
2. High-Resolution AFM
For High Resolution I didn't find any publication and ideas, almost every author say they use FFT and Gwyddion software for making images better. Please suggest me some topics for my MS thesis. I have AFM Device and my lab has almost all the necessary tools and components to work with it.
It is an old AFM system with no technical support available anymore. I would like to start a discussion thread for the researchers still using it and discuss the issues faced while using the equipment. Currently, I am facing issues with the friction images.
I use NaioAFM from Nanosurf company. please how I can get a solution for the background noise (electronic noise) during measurement.
PID parameters are
Scan rate 1 sec/line
I typically use sharp AFM probes to do friction measurements on silica. I blunt the tips somewhat and convert the apex to thick silica by annealing in air at very high temps, which produces a very smooth apex. Unfortunately, in recent experiments, the wear rate rapidly converts the tip to a punch which creates all sorts of problems for me.
I was hoping to work around this problem by moving to sililca colloidal probes, which are very common of course. My question is what is/are good supplier(s) to obtain colloids in an appropriate size range (10-50um I guess) for gluing to AFM cantilevers, and critically, with very low roughness values (<1 nm at least) to make the contact mechanics comprehensible, and ideally though perhaps not critically, without the the substantial fraction of Na that is inherent to the synthesis of many colloidal silicas.
Porosity is not a major concern unless it affects the roughness. I am having trouble locating appropriate suppliers for such colloids. Any tips would be greatly appreciated.
In a few articles, I have come across images that are similar to SEM cross-sectional images but taken with AFM, but the article does not mention the details. Can you help me to measure in this way?
Anybody has run into similar problema, recently we our research, we've runnning through this issue in the AFM images. They're distorted, elongated in the side, but the center seems to be ok.
We've tried to change the tip, the sample, faster scanning, let ir "rest" or use for longer times. But nothing seems to resolve.
Someone knows how to help, please.
We tested in 0º and 90º
I've been looking for methods for immobilizing 5'-Thiol modified dsDNA on gold slides. Most of what I've come across suggests using DTT followed by a desalting step or using TCEP. However, I haven't had any luck reducing and then conjugating the DNA onto the gold slides. I've seen some methods use DTT1,2, and some use TCEP3, and some include an incubation step with MCH2,3 after the thiol reducing step. It's been difficult finding a complete and satisfactorily detailed method online.
The DNA I am using is a 1 kb long double-stranded molecule with a 5'-Thio modification at one end and a 5'6-FAM modification at the other end. I need to synthesize the strands myself via PCR using two modified primers and a template strand rather than ordering the fully modified 1 kb strand, so my working concentrations are usually fairly low (~70-100 ng/uL after PCR and spin-column purification).
Can anyone provide a detailed method that has worked for them for reducing thiol modified DNA and immobilizing it onto gold surfaces or gold monolayers?
- Hegner, M., Wagner, P. & Semenza, G. Immobilizing DNA on gold via thiol modification for atomic force microscopy imaging in buffer solutions. FEBS Letters 336, 452–456 (1993).
- Ladik, A. V., Geiger, F. M. & Walter, S. R. Immobilization of DNA onto Gold and Dehybridization of Surface-Bound DNA on Glass. 5.
- Das, J. et al. Reagentless biomolecular analysis using a molecular pendulum. Nat. Chem. 13, 428–434 (2021).
Hi scientific community!
I was hoping to get some input on a problem I am currently having deciding how to fix my samples for AFM. I am using AFM to detect stiffness of the ECM in fibrotic areas, and have the option to leave my samples unfixed (we have tested that this works), or go for PFA, NBF or a solvent method like methanol.
Since we know methanol will dehydrate the ECM and PFA or NBF will cross-link it, we were intending to go straight for measuring the unfixed tissue, since this would be most "correct". However, whilst the main structural proteins like collagen will be fine for the time period of the AFM experiment if kept cool, it has come to my attention that other smaller, less stable ECM proteins could degrade if unfixed, which could affect the integrity of the fibrosis and therefore the resulting stiffness measurement.
Most previous literature either uses unfixed tissue or PFA.
What seems the best method to you - to fix the ECM, or to go ahead unfixed?
We are trying to compare these two systems in the process of purchasing one of them. Our applications revolve around surface roughness quantification, mineral wettability evaluation, and surface force measurements on rock samples. I would appreciate your expert views.
Dear All, can anyone explain to me how to measure the elastic modulus of a material through force-volume AFM curves? I am using Nanoscope Analysis software but the results seem not to be accurate.
Nanoindentation is a attachment with AFM or it is a separate testing procedure? Nanoindentation gives property at nanolevel? Young's modulus, Hardness, Stiffness, Load vs Depth, Load Vs Hardness properties alone cane be obtained using nanoindentation or any other properties can also be known using nanoindentation? Where I can get all these things done in India? Please share your suggestions. Many of the prestigious institutions saying machine under maintenance, machine not working or operator not available.
I want to calculate Skewness parameter. The data obtained from AFM is consist of Ra, Rq, Rp, and Rv. It does not measure Rsk. How can I calculate Rsk from Rq numerically?
I am trying to perform covalent immobilization of streptavidin protein on glass surface. This is done by first coating the glass with 2% APTES-toluene and then with 2.5% glutaraldehyde-water solution. Then I add the streptavidin which is in PBS (pH 7.4) on the glass coverslip. This doesn't seem to work. Please let me know the right pH, salt and temperature conditions that are appropriate for the reaction between glutaraldehyde and amine groups created by APTES coating on glass.
Specially with "HRTEM" it'is quite difficult get high resolution morphology in real sense!! Or the require knowledge, expertise is lacking off? Let produce a significant and directional concluding discussions here!!! This is my earnest appeal to all
The tip will be used for scalpel AFM technique but its contaminated with Si. I have tried with low conc. of HF and sulfuric acid in ultrasonication, but the cantilever itself blew away. Normal water or acetone with ultrasound also didn't work.
Is there any easy option for the cleaning, either wet or dry?
Describing some easy option rather than sharing some scientific article, will be greatly cheered :)
I have this issue with drying short DNA fragments on mica for AFM experiment.
As you can see DNA in this AFM image DNA has a preference to face in a certain direction.
I think it was caused by solution drying with nitrogen gas gun. Nitrogen gas perhaps pushes away the solution in a direction along with DNA.
How can I avoid this orientation skewness?
Can anyone suggest a formula/method/technique to calculate the spring constant and also resonance frequency of an AFM cantilever after metal deposition?
Thanks in advance,
I've interested in being able to conduct TEM analysis on my AFM probes after use. I'm currently struggling to find a way to mount the AFM probes into a TEM sample holder that normally accepts TEM grids. Has anyone had success doing this? Thank you.
We have a new AFM with a capability to achive high resolution images (up to 50nm). The AFM tips can scan the surface of the object and as well, can penetrate into the object. We also have the capability to use the tip for scanning planktonic bacterial cells inside a medium.
During AFM imaging, the tip does the raster scanning in xy-axes and deflects in z-axis due to the topographical changes on the surface being imaged. The height adjustments made by the piezo at every point on the surface during the scanning is recorded to reconstruct a 3D topographical image. How does the laser beam remain on the tip while the tip moves all over the surface? Isn't the optics static inside the scanner that is responsible for directing the laser beam onto the cantilever or does it move in sync with the tip? How is it that only the z-signal is affected due to the topography but the xy-signal of the QPD not affected by the movement of the tip?
or in other words, why is the QPD signal affected only due to the bending and twisting of the cantilever and not due to its translation?
I have got the FM and AFM1 configurations and able to optimize by giving MAGMOM. But how to get AFM 2 and AFM 3 ? and how the MAGMOMS are to be provided? I need step by step procedure. Thank you.
after the interaction of drug the enhancement in the SPR band was observed the intewraction was proved by FTIR and AFM the AFM resiults shows aggregation of NPs the of NPS increases from 40nm to 200 studied bty AFM i also study time depedent interaction of drug and nanoparticles the DLS spectra showing abrupt results how to interpret the results.
DLS result attached plz guide
I have grown Ge on glass with in-situ annealing. firstly the rms roughness and height decreases then increases with temperature while grain size increases for all temperature.
I am quite new to AFM imaging and I'm having struggles in getting accurate topography images to measure surface roughness. My issue is that even though I it seems that the trace and retrace profiles match I am unsure if I accurately traced the surface or the image is an artifact. I'd like to ask for any tips or suggestions?
The afm machine is bruker multimode afm.
The mode I normally use is air tapping mode.
I've been trying to do this for years. The recommended way of using curved tweezers to grab it near the back gets me way less than 50% success. Cantilever tweezers dont work because the probe is too recessed. I've tried grabbing from the front with self-locking and normal sharp tweezers. I have somewhat unsteady hands, but they aren't that bad. I am 95% successful on the Asylum MFP3D, as long as I remove the metal tongue contraption completely first.
Any tips aside from the ones above that don't work for me?
I often need to use the same tip more than once lately for technical, not financial, reasons, so the current situation is untenable.
I would like to perform surface roughness of natural fibers by either using AFM or Laser micrsocpy, what are the main sample preparation steps involved for better results and accurate measurement?
I am working on Casimir and Double layer force in liquid(water) by AFM, but many bubbles appear after injection of water into the AFM tip holder, I am not able to remove air bubbles from the water. Is there any way I can remove bubbles from water?
tapping mode tips are too stiff to measure extracellular matrix roughness. I am looking to find the right cantilever type with a stiffness (k-value) that is able to do so in solution.
Thank you in advance
I need to open and elaborate a force-distance curve measurement file with Gwyddion.
How can I normalize the raw data, apply a model (e.g. Hertz) and get mechanical info of the material behavior (elastic modulus and adhesion force)?
I am getting different roughness values for same sample surface by Taylor Hobson surface profilometer and AFM. Approximately half the roughness value coming in case of AFM as compared to surface profilometer. Why is this happening, please answer about it, I have to put a specific reason in my journal.
Has anybody run into similar issues with regards to the Nanoscope III where, when scanning, the image is seemingly elongated as seen in the image below? Having run through the manual and other forums we have restarted the AFM many times, let the laser heat up, left it off over the weekend, and have still run into this issue. Since the Nanoscope will start working sporadically from time to time, the tip is likely not the problem. Does anyone have any recommendations or thoughts as to what the issue could be?
I'm trying to get a monolayer and far a part of 100 nm polystyrene beads on mica, I diluted the beads with MilliQ Water, and I tried different concentration but I ended up with multilayers in the most areas of the mica.
My experiment should be done in liquid and an ambient conditions and it requires the polystyrene beads on mica like the image attached.
Hello. Is there any way we can find the surface area of a roughened surface? Is there a certain constant that we can multiply by the surface roughness to get a measurement of the surface area?
Any non-AFM ideas?
Thank you for your time,
In AFM analysis under hybrid parameters there is a term called average profile wavelength which involves both amplitude and space parameters.
I am unable to understand the physical significance of the same. Can someone please explain the term in simple words ? In its equation La = 2pie Ra/delta a what is denominator term ?
If I want to do surface characterization of a material which characterization technique is better SEM or AFM and why? All relevant answers are appreciated!
I am trying to draw schematics of a droplet attached to the cantilever of an atomic force microscope (AFM). Can anyone please introduce a software for this purpose?
I have certain metallic films treated via ion beam irradiation. I am analyzing the evaluation in topographical features. I have used NANOSURF FLEX AFM for the particular characterization. For analysis, I am using the recommended software which comes with the system. We are provided with different options (filters & signals) to present our micrographs. When we change these options, the area roughness changes significantly. For example, choosing the default setting of line fit shows normal roughness, however, changing the filter to derived data also changes area roughness decreases. Similarly, when we change the signal type from the z-axis to amplitude or phase, the roughness also changes.
I have consulted the literature and found that different approaches are used in different studies. I will definitely report the filters and signals I will be using for analysis. My question is which option is most viable for absolute area roughness.
To achieve superlubricity in two-dimensional heterostructures, do we need to stack it at a certain angle? or directly through mechanical exfoliation, we can achieve superlubricity in 2D heterostructures. Please provide some useful suggestions.
I am aware of the concept of commensurate and incommensurate, but in the heterostructure, do we need to follow that?
Hello! I've been a little confused recently with some obtained data. The related question is, can roughness of a spin coated and highly uniform film be larger than the thickness of the film? For instance, if the film thickness is 20 nm, can roughness be 25 nm?
The diameter of kapok fiber is of the order of 30 micrometer-50 micrometer and there are some nanoscaled wrinkles on the surface of micro-scaled fibers.
I have used some physical and chemical treatments to modify the surface of kapok fiber(to increase surface roughness). AFM can be used for imaging at nano-scale order.
How can I study the surface morphology of kapok fiber using AFM??