MEMS, golf swings and haircuts

Citation

Loughlin, C. (2007), "MEMS, golf swings and haircuts", Sensor Review, Vol. 27 No. 1. https://doi.org/10.1108/sr.2007.08727aaa.001

MEMS, golf swings and haircuts

A lot is happening in the field of micro electrical mechanical systems (MEMS) and nanotechnology. Accelerometers were one of the earlier applications but to me one of the more recent and most exciting developments is in the use of MEMS technology to create sources of power.

You generally know you are doing something right when you manage to turn a disadvantage into something really useful. This is very much the case with MEMS generators that turn vibration into electrical energy. The power available may be just a few hundred microwatts, but this is enough to supply a sensor and a wireless transmitter. This means that you could obtain sensor data forever without any need to run cables or include batteries.

Basic laws of physics tell you the amount of energy you can get out of a vibrating object and until very recently the numbers simply did not add up. However, it is the development of very low power electronics that has made MEMS power sources worthwhile.

Numerous designs for powers sources are hitting the headlines. Some simply rely on vibration to either move a coil in a magnetic field or to waggle a piezoelectric element. Others, such as the research by Alan Epstein at MIT are more adventurous and aim to produce a MEMS gas turbine powered by ethanol.

I predict that MEMS power sources will soon become as ubiquitous as the digital watch that they could power – but what of MEMS sensors themselves?

Given that the second “M” in MEMS stands for “Mechanical” it is reasonable to assume that the sensors will be in some way concerned with mechanical movement. Accelerometers, vibration sensors and pressure sensors are already around, but what else can we do with them?

This year I spent a day at the UK Open Golf Championship and I must confess that gathering material for this journal was not high on my list of priorities. However, I did pass by the Callaway stand and was rather impressed to watch a system that analysed golf swings or more accurately, golf ball trajectories. As a (hopefully informed) observer I had no idea how the system worked as there were no obvious flashing lights or cameras or laser beams. The actual ball that was hit only went a few metres before hitting a safety net, but on the screen behind, the virtual ball continued along the displayed fairway. Hooks and slices were analysed with ruthless efficiency.

Our feature article by Christine Connolly “A Golf Swing Analysis Tool from Callaway Golf” describes how the system works.

This reminds me of one of the most successful early applications of machine vision which was in hairdresser salons. Pictures were taken of the expectant hirsute customer who could then see her (I do not think it caught on with men) image with a wide variety of new styles and colourings.

I doubt if the developer of the 3D tracking system that comprises the Callaway system always intended it to be used for helping us with our golf swings, but that is the nice thing about working on new technology. It is not until you have the tools in your toolbox that you find out how useful they are.

Clive Loughlin