
OMCL-TR400PB
OLYMPUS pyramidal tip with gold coating designed for contact mode operation. The picture below (left) is an SEM image of a sharpened pyramidal tip with tip-side coating of gold. As in the picture, the pyramidal tip is sharpened toward the tip apex. The tip has an uneven surface due to the gold cluster. (The right image is of the standard pyramidal tip without gold coating.) Two pairs of different shapes of triangular cantilevers protrude from both sides of a glass chip. Lever thickness: Four different shapes of rectangular cantilevers protrude from a glass chip. Lever thickness: Thin gold/chromium film is coated on the back side of the cantilevers for reflecting light from a deflection sensor in the AFM equipment. Thin gold/chromium film is also coated on the tip side of the cantilevers in the series of OMCL-TR/RC***PB- types. Because of the over coating on the tip side, the radius of the tip of the OMCL-TR/RC***PB- types become blunter, 40 nm or less, than that of OMCL-TR/RC***PSA- types, 20nm or less. Below is the gold thickness on the levers of the tip side. According to the tip sharpness described above, the gold thickness at the tip apex must be thinner than those values. Either triangular or rectangular cantilevers extend from a glass chip. Each chip is connected at the bottom of the glass chip and makes a chip array (call it "cantilever strip"). The left illustration shows a part of the array of rectangular cantilever chips. Stiffness [N/m] and resonant frequency [Hz] of each cantilevers are Calculated values under the vacuum condition, or no-damping condition. note:for DC (contact) mode AFM and LFM
Catalog number
Small quantily unit
wafer unit
34 chips/unit
Not available now
Soft type
OMCL-TR400PB-1
-
Standard type
OMCL-TR800PB-1
-
LFM type
OMCL-RC800PB-1
-
SEM image of sharpened pyramidal tip
Tip
Dimensions of levers
Cantilevers of OMCL-TR series
400nm and 800nmCantilevers of OMCL-RC series
800nmMetal coating
[Reflex coating]
[Tip side coating]
OMCL-TR400PB-
OMCL-TR800PB-
OMCL-RC800PB-
Gold thickness on Tip-side (nm)
40
50
50
Dimensions of chips (substrates)
Mechanical properties of levers and tips
Lever
Tip
thickness
(nm)length
(µm)width
(µm)spring const.
(N/m)resonant freq.
(kHz)height
(µm)radius
(nm)
Triangular cantilever with reflect coating
OMCL-TR400PB-
400
100
200*
0.09
0.0232
102.9
30
OMCL-TR800PB-
800
100
200*
0.61
0.1668
222.9
30
Rectangular cantilever with reflect coating
OMCL-RC800PB-
800
100
100
200
20020
40
20
400.42
0.82
0.06
0.1164
66
17
172.9
30
The resonant frequency of each of the cantilever shift lower in water than in air because of the water damping. For instance in OMCL-TR400PSA-, the resonant frequencies of the 100µm and 200µm long cantilevers shift around 7kHz and 3kHz in water respectively.Applications
Silicon nitride tips sometimes stick to sample made of silicon nitride during the scanning. Gold coating works as a solid lubricant to avoiding this.
These gold coated tips are recommended because utilzing gold for this purpose is a very familier protocol among biologists and chemists. In force curve analysis to estimate a binding force between molecules, the functionalized tip is often used.