High bandwidth amplitude estimation lock-in amplifier

High bandwidth amplitude estimation lock-in amplifier

Atomic Force Microscopy (AFM) is an instrument used for imaging, analysing and manipulating matter at the nanometer scale. Dynamic mode AFM techniques offer the advantage of reduced tip-sample forces, which minimises damage to the tip and sample. The tapping mode (or semi-contact mode) works well in ambient air and liquid environments.

The invention is a technique to perform high-bandwidth amplitude estimation in dynamic mode AFM.

This estimation method has been recognised as one of the bottlenecks in AFM. Higher estimation bandwidths potentially enable much higher scan speeds. It is expected that by applying this new technique in a current AFM, the scanning rate could be significantly improved.

Inventors

Mr Kai Karvinen, School of Electrical Engineering and Computer Science, University of Newcastle, Australia.

Professor Reza Moheimani, School of Electrical Engineering and Computer Science, University of Newcastle, Australia.

Patent

An Australian Provisional Patent has been applied.

Features and benefits

Potential for digital implementation following analog demodulation

Minimal cost of implementation but enables a significant increase in estimation bandwidth

Compatible with both high-speed AM-AFM and multi-frequency AFM

Market value and size

The scanning probe microscope market is $470 million in 2010 with a compound annual growth rate expected of 14.7%. The AFM market accounts for two-thirds of the scanning probe microscope market.

Potential application and market opportunities

Some of the major market and technology trends in the scanning probe microscopes market are:

Surface imaging (e.g. polymer, metallurgy and others)
Semiconductor’s product inspection and failure analysis
Biosciences industry (biological cells and DNA)
It is envisioned that this technique will find applications in other fields which require a high-bandwidth lock-in amplifier.

Development stage

Working prototype has been developed at the laboratory scale with good results. Now requires scale-up for commercial application.