Tag Archives: partial coating

Partial Coatings of AFM Cantilevers II

Zeno Schumacher, Yoichi Miyahara and Peter Grütter from McGill University, Montreal together with our colleague Laure Aeschimann from NANOSENSORS™ are showing in their current publication “Improved atomic force microscopy cantilever performance by partial reflective coating” (Beilstein J. Nanotechnol. 2015, 6, 1450–1456) the advantages of partial coated AFM cantilevers.

Force noise of cantilevers with different coating coverage percentages measured in high vacuum. From: Beilstein J. Nanotechnol. 2015, 6, 1450–1456.
Force noise of cantilevers with different coating coverage percentages measured in high vacuum. From: Beilstein J. Nanotechnol. 2015, 6, 1450–1456.

Beside the close-to-original Q-factor of partial coated cantilever a reduced low-frequency noise is the second big advantage of a partial coated cantilever. The figure is showing noise spectra of soft cantilevers with different coating coverages acquired in air. The fully coated cantilever shows the highest 1/f noise. The 1/f noise reduces with reduced coating coverage. The uncoated cantilever shows the lowest 1/f noise level. When comparing the fully coated with the uncoated cantilever a difference of an order of magnitude could be observed.

This reduced force noise will enhance the cantilever sensitivity for contact mode imaging and force spectroscopy measurements dramatically.

The original article can be found on the Beilstein Journal of Nanotechnology website

Partial Coatings of AFM Cantilevers I

Zeno Schumacher, Yoichi Miyahara and Peter Grütter from McGill University, Montreal together with our colleague Laure Aeschimann from NANOSENSORS™ are showing in their current publication “Improved atomic force microscopy cantilever performance by partial reflective coating” (Beilstein J. Nanotechnol. 2015, 6, 1450–1456) the advantages of partially coated AFM cantilevers.

Q-factors of NCLR cantilevers with different coating coverage percentages measured in high vacuum. From: Beilstein J. Nanotechnol. 2015, 6, 1450–1456.
Q-factors of NCLR cantilevers with different coating coverage percentages measured in high vacuum. From: Beilstein J. Nanotechnol. 2015, 6, 1450–1456.

They coated cantilevers with coating coverages from 15 to 100% and measured low-frequency noise and Q-factors. In the graph above shows the Q-factors of NCLR cantilevers with different coating coverage percentages measured in high vacuum. A 30 nm Al coating was added to a 7 μm thick NANOSENSORS™ NCLR cantilever. Adding a complete reflective coating to the cantilever will reduce the Q-factor by half compared to the uncoated cantilevers. By minimizing the coating to 20% of the cantilever length the same Q-factor as that of the uncoated cantilever can be achieved.

The original article can be found on the Beilstein Journal of Nanotechnology website

NANOSENSORS™ Uniqprobes®: Partially Coated Cantilever for Advances in Life Science AFM

Often it is necessary to add a coating to an AFM cantilever. In most cases it is a reflex coating on the backside of the cantilever to enhance the reflection of the laser to get a sufficient signal into the AFM photodetector.

Cantilever with partial coatings, varying from 20 to 100%.
NANOSENSORS™ cantilever with a reflex coating covering about 20, 40, 65 and 100% of the cantilever.

Unfortunately, adding a coating to a cantilever has several drawbacks such as:

  • a coating adds stress to the cantilever
  • when the cantilever is illuminated with the laser the so called Bimorph-Effect (if operating in liquids) will bend the cantilever and let the laser drift out of the photo-detector (thermal drift)
  • a higher damping of the cantilever which leads to a lower Q-factor
  • a higher noise of the cantilever

Those effects can be reduced dramatically when the coating is not done on the whole cantilever, but only on a part of it. The images above are showing cantilevers with a reflex coating covering about 20, 40, 65 and 100% of the cantilever.

To provide best quality with highest possible cantilever sensitivity NANOSENSORS™ manufactures their Uniqprobe® cantilever as the only AFM tip exclusively with a partial coating!

To learn more, please have a look at

the NANOSENSORS™ Uniqprobe® brochure