July 19, 2017

How small is small enough?

New book outlines latest developments in tools and techniques for miniaturisation of devices.

From the first computers that filled a room to processing power smaller than a thumbnail, scientists have continually developed new ways to make devices smaller.

The trend for miniaturisation has found applications in a broad range of medical, energy and engineering applications and has posed many challenges in the production of micro components with complex shapes and high engineering performance requirements.

Professor Zhengyi Jiang, from the University of Wollongong’s (UOW) Faculty of Engineering and Information Sciences, said product miniaturisation is enabling product structures and functions to be implemented on microscale forms shapes and sizes, aimed at reducing product weight, volume, cost and pollution.

Professor Jiang said miniaturisation was achieved by reducing the size of the entire system, including materials, processes, tools, machines and equipment.

“Forming technology and theory established in the macro world cannot be simply scaled down to the micro world to make high-quality miniaturised products because it is impossible to scale down all parameters in the microforming process,” Professor Jiang said.

To that end, advanced and high-precision devices must be redesigned and the UOW team has successfully designed a number of advanced microforming devices, including various types of micro rolling mills.

It also means building and disseminating knowledge of the theory and processes. Professor Jiang and colleagues Dr Jingwei Zhao and Dr Haibo Xie have recently published the book, Microforming Technology: Theory, Simulation, and Practice, which provides an accessible introduction to the theories and techniques for miniaturisation, known as microforming.

The book is designed to provide engineers, scientists, academics and graduate students with a comprehensive understanding of microforming fundamentals and theory, numerical process modelling and simulation, as well equipment and tool design and practical microforming process technology.

Professor Jiang said the book was a timely capture of state-of-the-art developments in microforming technology as demands increase for micro components for diverse products including medical devices, precision equipment, communication devices, micro-electromechanical systems (MEMS) and micro fluidics systems (MFS).

Professor Jiang’s group has successfully manufactured high-quality ultrathin metallic foils with thicknesses of less than 40 micrometres, or four thousandths of a millimetre, and a shaft with a diameter of less than half a millimetre (0.4 micrometres).

The team has also successfully fabricated long and tiny high-quality micro cups with a cup diameter of 0.5 mm.

“Challenges remain in the high efficiency manufacturing of high-quality micro products due to the common problem of microscale size effects, complexity of processes for making micro products and the ever-increasing requirement to improve product quality and performance,” Professor Jiang said.

Some of these challenges in microforming are being addressed through extensive numerical and experimental work, and they have successfully used seven different microforming methods, including micro cross wedge rolling, micro flexible rolling, micro ultrathin strip rolling, micro deep drawing, micro hydromechanical deep drawing, micro bending and micro compression, to fabricate high quality micro products.