Novel instrumentation for high-speed AFM-based nano machining.
Dr Emmanuel Brousseau from Cardiff School of Engineering has been awarded £314k from the Engineering and Physical Sciences Research Council (EPSRC) to investigate the development of high-speed (AFM) probe-based mechanical machining at nano scale.
The project started in October 2015 and will run until October 2018. It is led by Dr Brousseau and also involves Dr Dan Read from Cardiff University’s School of Physics and Astronomy and Professor Chris Bowen from Bath University.
The development of novel and disruptive nano-scale manufacturing technologies is a research area of high importance. Although vacuum and mask-based lithography techniques are already employed in industry for nano-scale manufacturing of semi-conductor devices and the derived nano electro mechanical systems (NEMS) components, they still have a number of limitations associated with them.
In particular, these fabrication technologies rely on capital-intensive equipment while being restricted to the fabrication of planar features and constrained to a limited set of processed materials. Besides, there are also increased concerns over their environmental friendliness as they are energy and resource intensive and generate significant waste.
In this context, this project focusses on the development of high-speed AFM probe-based mechanical machining at the nano scale. The process represents an alternative and innovative solution that can potentially address the lack of cost effective, 3 dimensional and more environmentally friendly fabrication technologies for producing nano-structured components in a wide range of materials.
However, to fully realise the potential of AFM probe-based machining, a step-change in its throughput is still required. For this reason, the research put forward in this project aims to develop a new actuation module (Fig.1) that could be readily fitted on commercial AFM instruments to reach untapped processing speeds when conducting tip-based machining operations.
This new actuation device, which will rely on piezo-electric actuators, will be fixed onto the stage of AFMs and will be used to create fast rotating displacements of a processed sample with respect to the tip of an AFM probe.
The vision is to enhance the capability of current AFM systems by enabling them to perform nano-scale material removal operations at cutting speeds a thousand times faster compared to state of the art in this field.
In particular, the developed set-up will be designed so that it enables cutting speeds from a few m/min up to a few hundreds of m/min to be reached.
Two major advantages are envisaged with the development of this new set-up. First, it will provide a cost-effective and environmentally friendly alternative to vacuum and mask-based lithography techniques for nano-scale fabrication. Second, due to the fact that AFMs are widespread in research laboratories, it will contribute to broaden the base of users with in-house manufacturing capabilities for the nano-machining of components with sub-micrometre structures.
Initial results from the project have shown that a theoretical cutting speed over 5 m/min could be achieved with this new set-up (Geng et al., 2018). This is significantly better than the state of the art for AFM-based nanomachining, which was less than 1 m/min.
Geng Y., Brousseau E.B., Zhao X., Gensheimer M. and Bowen C.R. AFM tip-based nanomachining with increased cutting speed at the tool-workpiece interface. Precision Engineering, Vol. 51, 2018, pp. 536-544
For further information about this project, please contact Dr Emmanuel Brousseau.