Name: atomic force microscopy for surface mapping
Uploaded: 2023-04-30T12:00:37.000Z
Duration: 1 min 8 s
Channel: JoVE

Atomik kuvvet mikroskobu veya AFM, nanometre çözünürlüğe sahip bir numune hakkında topografik bilgi sağlamak için bir nanoprob kullanarak bir görüntü oluşturur.
Optik mikroskop 1000X'e kadar büyütebilirken, AFM'nin büyütme potansiyeli 1.000.000X'e kadardır.
AFM, hem sabit hem de canlı örneklerin görüntülerini oluşturarak, aktin dinamikleri gibi dinamik hücresel süreçleri yakalamasına olanak tanır.
AFM nanoprobu, esnek bir konsolun ucuna takılır ve birlikte numuneyi tararlar. Prob, numune yüzeyinin dış hatlarını takip eder, yukarı ve aşağı hareket eder ve bu da konsolun yerini alır.
Bir AFM tipinde, bir lazer ışını konsola yöneliktir ve hareket ettikçe lazerin yansıması da hareket eder.
Konuma duyarlı bir fotodetektör, lazer ışınının sapmasını kaydeder.
Veriler, numune yüzeyinin üç boyutlu bir görüntüsünü oluşturmak için yazılımın işleyebileceği bir bilgisayara gönderilir.

<ol>
	<li>Casuso, Ignacio, Felix Rico ve Simon Scheuring. "Biyolojik AFM: nereden geliyoruz - neredeyiz - nereye gidebiliriz." Moleküler Tanıma Dergisi 24.3 (2011): 406-413.</li>
	<li>Garcıa, Ricardo ve Ruben Perez. "Dinamik atomik kuvvet mikroskobu yöntemleri." Yüzey bilimi raporları 47.6-8 (2002): 197-301.</li>
</ol>

atomik kuvvet mikroskobu

Atomic Force Microscopy

Atomik kuvvet mikroskobu (AFM), seramik, cam, polimerler ve biyolojik örnekler gibi çeşitli örneklerin topografik ayrıntılarını analiz edebilen bir tür taramalı prob mikroskobudur. AFM, optik görüntüleme sistemine göre 1000 kat daha fazla çözünürlük sunar. AFM'den oluşturulan görüntüler üç boyutlu yüzey profilleridir ve diğer görüntüleme tekniklerinden elde edilen düz, iki boyutlu görüntülere göre avantaj sunar. AFM Probu Prob, herhangi bir AFM kurulumunun kalbi olarak kabul edilir ve konsol ve uç tertibatından oluşur. Problar bu tür mikroskoplarda en sık değiştirilen parçadır çünkü numunelerle sürekli etkileşim, ucu aşındırır. Bu nedenle prob için malzeme seçimi numunenin özelliklerine bağlıdır. Sert numuneleri analiz etmek için kullanılan silikon problar, daha yumuşak numuneleri taramak için daha uygun olan silikon nitrür problardan daha sert ve keskindir. Bu keskin uçlar, daha yüksek doğrulukta analiz için elektrokimyasal aşındırma veya karbon nanotüpler kullanılarak üretilir. AFM'nin Görüntüleme Modları AFM'de yüzey topografyası, prob ucu ile numune yüzeyi arasındaki etkileşim kullanılarak incelenir. İki ana görüntüleme modu vardır: temas modu olarak da adlandırılan statik mod ve dinamik mod. Statik veya temas modunda probun ucu numune yüzeyi ile sürekli temas halindedir. Uç yüzey üzerinde sürüklendikçe, numune ile uç arasındaki itici kuvvetler konsolun bükülmesine neden olur ve bu da kaydedilir. Numune yüzeyinin tamamı, raster tarama adı verilen hem x hem de y eksenlerinde ileri geri taranır, konsolun dikey hareketi ise z eksenini kaydeder ve böylece 3 boyutlu bir görüntü oluşturulur. Dinamik modda, prob numune yüzeyinin hemen üzerinde salınır, yüzeye yaklaşır ancak yüzeye temas etmez. Çekici ve itici kuvvetler, uç ile numune arasındaki mesafenin değişimini belirleyerek konsol salınımının genliğini etkiler. Bu geri bildirim, numunenin yüzey topografyasını oluşturmak için kaydedilir.

Atomik kuvvet mikroskobu

Atomik kuvvet mikroskobu (AFM), seramik, cam gibi çeşitli numunelerin topografik ayrıntılarını analiz edebilen bir tür taramalı prob mikroskobudur.

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atomic force microscopy for surface mapping

Atomic force microscopy is used to map the surface details of materials. It can examine ceramics, glass, polymers, and biological samples. The method gives far more resolution than an optical imaging system and produces three-dimensional surface profiles instead of flat 2D images.

The probe is the key part of an AFM setup. It includes the cantilever and tip assembly, and it is also the part that is replaced most often. Constant contact with samples wears down the tip, so probe choice depends on the sample being scanned. Silicon probes are stiffer and sharper, which makes them useful for hard samples. Silicon nitride probes are better for softer samples.

AFM tips can be made with electrochemical etching or with carbon nanotubes to improve accuracy. The microscope reads surface topography by tracking how the probe tip interacts with the sample surface. This interaction is recorded as the probe scans across the surface.

AFM uses two main imaging modes. In static mode, also called contact mode, the tip stays in continuous contact with the surface. As it drags across the sample, repulsive forces bend the cantilever, and that bending is recorded. The sample is scanned back and forth in the x- and y-axes, which is called raster scanning, while the vertical motion of the cantilever records the z-axis and builds a 3D image.

In dynamic mode, the probe oscillates just above the sample surface. It comes close to the surface without touching it. Attractive and repulsive forces change the distance between the tip and the sample and affect the oscillation amplitude. That feedback is then used to construct the surface topography.

Atomic Force Microscopy for Surface Mapping

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atomic force microscopy

Atomic force microscopy is used to map the surface details of materials. It can examine ceramics, glass, polymers, and biological samples. The method gives far more resolution than an optical imaging system and produces three-dimensional surface profiles instead of flat 2D images. The probe is the key part of an AFM setup. It includes the cantilever and tip assembly, and it is also the part that is replaced most often. Constant contact with samples wears down the tip, so probe choice depends...

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key terms and concepts

Learn how atomic force microscopy maps surfaces, why probe choice matters, and how contact and dynamic modes build detailed 3D images of samples.

Atomic Force Microscopy for Surface Mapping | JoVE K12

cell biology

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Atomic Force Microscopy for Surface Mapping

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