Tool-Based Micro/Nano Machining: Development of Innovative Machine and Machining Processes

It is an unarguably fact is that the current trend in manufacturing is miniaturization of products with extreme surface finish. I addition, the surface finish and dimensional accuracy requirements of products as well components are getting remarkably stringent, especially in the areas of vision, information, biotech, environmental, measurement and medical industries. Moreover, these products need to accommodate increased number of functions. Production of such products and parts of micron level size with very high dimensional accuracy of nano meter level is getting more importance because of a steadily increasing demand for such industrial products. To satisfactorily meet these challenges micro/nanomachining technology must be developed. Such machining is usually performed either using techniques based on energy beams (beam-based micro-machining) or using solid cutting tools (tool-based micro/nanomachining). Some of the limitations of beam-based micromachining are due to poor control of 3D structures, low aspect ratio of products and also low material removal rate. In addition, special facilities are required to perform these processes and the maximum achievable dimensions are relatively small. However, with the application of tool-based micro/nanomachining technology some of these limitations can be satisfactorily overcome using ultra precision machine tools and solid cutting tools to produce the micro-features with well-controlled shape, features and tolerances. In many cases, compound or hybrid or simultaneous machining process is required for effectively performing micromachining. To meet the challenges, multi-process machines are required and unfortunately such machines are not available. Consequently, the author will present the development of a first-of-its-kind multi-process machine tool and the innovative approaches to develop various compound, hybrid and simultaneous machining processes for the successful implementation of micromachining. Recently, nanomachining of difficult-to-machine materials is also getting more importance with the pervasive demand for fabrication of miniature, thinner and lighter products, intricate micro-shapes and structures on such materials. In addition, the products also require nano meter level surface finish. The author would like to present his contribution especially in the area ductile mode machining of brittle materials. This paper also presents the recent developments in the areas of deeper understanding of the mechanisms and machining technologies to generate nano-finish surface by machining processes. In this paper, the basic understanding of nanomachining mechanism, `extrusion-like' chip formation metal cutting is briefly discussed. With the emergence of hybrid freeform surfaces to increase the optical performance and to provide new functions. To fulfill these objectives, the author and his team have carried out ultra-precision machining using fast tool servo (FTS) and slow slide servo (SSS) mechanisms. Some typical examples of the development of innovative nano machining processes and products have been presented in this paper. Finally, the development of a rotating tool for continuous production of radial Fresnel lenses has been presented.