NanoTooling

Cost effective and scalable manufacturing techniques are required to integrate components with nano scale features into products, and thus to broaden the range of applications where nanotechnology-based devices are utilised. To address these needs, the research community has developed and is still investigating process chains that represent production platforms for serial manufacture of nano structured components. The aim is to combine in these chains the capabilities of master-making methods with those of high throughput replication technologies such as thermal or UV imprinting or micro injection moulding. To fabricate the necessary nano structured replication moulds, most process chains employ lithography-based pattern transfer techniques, and more recently direct write processes, e.g. Focused Ion Beam (FIB) machining. A common characteristic of all these master making technologies is that they rely on capital intensive equipment and necessitate particular operating temperatures or vacuum conditions. The high capital investment needed to acquire, operate and maintain such equipment represents a major obstacle in many nanotechnology application areas. As a result, this could hinder the development of new or improved nanotechnology-enabled products. For this reason, it is desirable to develop alternative process chains that incorporate widely used and relatively simple master making techniques for the fabrication of nano-structured replication moulds. Consequently, such process chains will enable the rapid and cost effective replication of nano structured components. One of the candidate technologies for the fabrication of such replication masters is the Atomic Force Microscopy (AFM) scratching process, as it allows material on the surface of a sample to be moved or removed at the nano scale. Due to the fact that the technique is relatively simple and AFM instruments are widespread in research laboratories, such an approach could offer a fast and cost-effective route for the fabrication of nano structured masters. Recent experimental studies have demonstrated the potential of the AFM scratching process to prepare replication moulds in relatively soft materials, and thus to produce small batches of nano structured polymer components.In order to make this promising technology economically viable, it is important to ensure that it can be applied on suitable master materials for the medium to large series production of polymer parts. Unfortunately, the crystalline structure of engineering materials commonly employed for such replication masters at the macro scale has a significant influence on the machining conditions at the nano scale. In particular, non-homogenous cutting conditions occur as the tip of an AFM cantilever moves across different grains. Thus, to produce nano structures reliably and accurately with this technology, it is necessary to adjust continuously the AFM scratching conditions to the materials' microstructure. Regrettably, no suitable models exist to describe and simulate this nanometric cutting process that take into account the microstructure of multiphase materials and its effects on the processing conditions.In this context, the proposed research programme will advance our understanding of this atomic level cutting process by modelling the physical phenomena that govern the mechanical interaction between the tip of an AFM cantilever and a workpiece material. The contribution to knowledge that is expected to result from this fundamental research will permit better control of the process when it is applied to produce nano structures in a broad range of materials, especially metals.

It is envisaged that this research programme will provide significant benefits to the manufacturing industry in the Micro and Nano Technology (MNT) sector, the academic community and ultimately to the wider society. Economic Impact - MNT manufacturing industry Given that AFM instruments are widespread in public and private research laboratories, the project outcomes can benefit a broad range of MNT users whose manufacturing needs at the nano scale cannot be met by commonly used lithography-based techniques. This potential is recognised by the project's industrial collaborators, namely the National Physical Laboratory and Quantulus Technology Ltd. Due to the fundamental nature of the research proposed, the impact of the project is expected to be witnessed by MNT companies first at laboratory-scale through proof-of-concept studies to develop miniaturised devices in materials such as metals or polymers. In the medium term, the process knowledge resulting from the project will have an impact on the serial manufacture of functional plastic components with nano scale features covering micrometre scale areas. In the long term, it is expected that innovative process chains for the production of masters employing AFM scratching as a component technology will be implemented in an industrial environment. These chains will be designed to enable the mass production of polymer components with complex three dimensional (3D) nano scale features patterned over relatively large areas. Thus, the project will contribute to the creation of capabilities for production of nanotechnology-based devices by providing a reliable manufacturing solution for the rapid and cost effective fabrication of nano structured replication masters. Societal Impact - Health and quality of life In the long-term, the wider society will also benefit from the proposed research programme. This should be achieved by enabling the development of novel nanotechnology-based devices with potential applications for improving public health, well being and security. Academic Impact - Contribution to knowledge and education In addition to the envisaged economic and societal impact, this project will also benefit directly the academic community engaged in nanomanufacturing together with the wider range of nanotechnology-based disciplines where the fabrication of nanostructured parts is required for experimental studies. Finally, the project will also benefit the training of future MNT scientists and engineers.