Thursday, 25 June 2015

Manufacturing Renaissance: 
Ubiquitous Instant Production (Part-IV)
Meso Engineering: Microelectromechanical Systems (MEMS).

‘Honey, I Shrunk the Kit!’ Begins a flippant metaphor of the miniature world of Microelectromechanical Systems or MEMS. A land of tiny machines so small you simply cannot see them with your bear eyes.

Imagine, if you will, peering at the common Dust Mite through a microscope. As you peer you see that the mite has one of its hairy-forelegs stood on the periphery of an even tinnier mechanical gear-wheel! Pan-out a little and view a playground of mechanical systems: intermeshing cantilevers and locks, pistons and wheels, cams and spinning gears resembling swings and round-abouts; with rack and pinions thrusting back and forth all at incredible speeds!

All this – believe it or not – describes the world of Meso-Scale engineering and is yet another promising advanced RM GigaMarket.

Meso-scale – which is not much talked about outside scientific or engineering laboratories – stands for the size range between micro (0.001mm) and nano (0.000,000,1mm); which is probably not much help for lay-reader. But believe it or not at that scale there is a lot of room. MEMS technology is a world of the very small: tiny functioning sub-assemblies and cute looking little components with dimensions much smaller than the thickness of a human hair.

Of course, you are going to ask ‘Way?’ What fuss and for what? Well to begin with, such assemblies are designed to sense and interact and feedback with the outside macro-world. Assemblies such as guidance systems, giro-servers, motion detectors, thermal meters, shutters, motors and servos that detect sub-microscopic dynamic ranges of sound, light, movement and vibration, whilst mechanically and electrically manipulating control systems across the nano-to-Meso-to-micro-scale and up!

Application examples include, accelerometers and motion detectors that are fitted in iPads for dynamic gamming modes, tri-axial accelerometer performance monitoring on snowboards competing in Olympic halfpipe contests, ultrasensitive hearing aid diaphragm mounting, retina injection contact lens mechanisms, 1000-thousandth of second lens shutter speed, and other Mission Impossible gadgets I cannot tell you about!

One of the most common materials employed is silicon; attractive in a wide variety of MEMS applications. It is an almost perfect Hookean material, meaning that when it is flexed there is virtually no hysteresis, hence almost no energy dissipation. This gives highly repeatable motion, suffers very little fatigue and can have service lifetimes in the range of trillions of cycles without breaking.

Medical science is benefiting enormously. Polymer-MEMS devices, for example, are widely used in cutting-edge surgery pathology. Constructed by submicron injection mouldings, embossing and stereolithography for application in microfluid devices such as disposable blood testing cartridges.

MEMS applications and the MEMS RM equipment itself, is a massively burgeoning industry as I write, that as high-end gadgets and tools shrink towards the invisible, is set to be pervasive and unstoppable GigaMarket.

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