AFM Cantilever
Active AFM Cantilever (AFM-CL)
Probes with piezoresistive read-out enable reproducible atomic-resolution imaging. The thermomechanical actuator integrated “on the probe” allows for excitation of the cantilever with its resonant frequency as well as seven or more eigen-modes. It makes static displacement possible without any interference to the mechanical AFM-setup. The piezoresistive Wheatstone bridge configuration of the read-out and the unique design enable effective temperature and actuator crosstalk compensation. Thermomechanical actuation is based on multi-layer structures composed of diverse thin film layers. Different coefficients of thermal expansion between the layers result in bending of the cantilever by means of differential extension of composite layers. In the context, the displacement of the cantilever tip can be precisely controlled by the dissipated electrical power in the embedded thin-film metallic resistor. nano analytik GmbH developed for its customers a series of small form-factor preamplifiers with high-bandwidth and low-noise performance, suitable for fast AFM applications. The preamplifier module has a small mass and can be integrated in any AFM-head in sample- and cantilever-scanning configuration.
Specification
| Cantilever Data | Value | Typical variation |
|---|---|---|
| Application | Non contact, contact mode (90° to Surface) | |
| Possible operating mode | Active / Passive | |
| Actuation | Integrated thermomechanically driven actuator | |
| Readout | Piezoresistive | |
| Material | Silicon | |
| Dimensions | W = 120 µm L = 350 µm T = 3 – 5 µm is possible | +/- 5 µm +/- 10 µm +/- 1 µm |
| Tip hight | 4.5 µm in plane | +/- 10% |
| Tip position from top | 3 µm | +/- 0.5 µm |
| Force Constant | Calibration on demand | +/- 10 N/m |
| Resonance Frequency | f = 30 – 110 kHz is possible | +/- 5 kHz |
| Possible Coatings | Upon request, reflective backside-coating of proven materials |
Gallery
The image shows the main components of nano analytik GmbH's active AFM cantilevers: The thermal actuator is able to statically deflect the cantilever as well as to oscillate it at high frequencies. The integrated Wheatstone bridge provides accurate and low-noise readout of the deflection.
