We received a number of very interesting submissions for ‘Innovator of the Year’ (2012). Unfortunately there can be only one winner, and after much deliberation the awards committee chose the submission entitled ‘Energy-modulated computing: a new paradigm for designing circuits and systems in energy-constrained environments’ by Prof. Alex Yakovlev and his team (Alex Bystrov, Terrence Mak, Delong Shang, Fei Xia, Andrey Mokhov, Danil Sokolov, Reza Ramezani, Abdullah Baz, Xuefu Zhang, James Docherty, Hock-Soon Low).
A fundamental aspect of digital electronic circuitry is the concept of a ‘clock’. This is typically a square-wave signal, to which digital circuitry responds by changing its state, usually at the voltage transition of the wave. The clock signal is typically generated by a quartz crystal – in effect a piece of rock – that vibrates at a precise frequency through a phenomenon known as the the piezoelectric effect. These clocks are nowadays very fast, so when we talk of a 1GHz computer CPU, this is on the order of the clock frequency. Naturally, we all want faster computers – but for a given device, a higher clock rate means more power. In this regard engineering processes (both software and hardware) can no longer sustain this growth; they need to be much more resource-conscious. Specifically, energy-frugal, power-proportional systems will be required in the future. As an example from the energy consumption viewpoint, the Google plant in Oregon has been estimated to require 103 million watts of power – enough to supply every home in Newcastle!
The innovative step pioneered by Prof. Yakovlev and his group concerns self-timed digital circuits. Such circuits are largely free from the constraints of a precise, predictable clock – i.e. they have timing elasticity. This allows such circuits to operate under a broad range of power and temperature conditions, which would defeat conventional circuitry. Unlike their conventional counterparts, these self-timed circuits also enable energy-proportional operation (i.e. energy consumption proportional to required activity). Such operation is of value in e.g. mobile devices, which require a high performance for short periods while interacting with the user, followed by relatively long idle periods that may last seconds or minutes. A natural, but previously unrecognised, effect of the new circuits is that they can actually convert electrical energy, in the form of charge stored in a capacitor, directly into computation. This effect has led Prof. Yokovlev’s group to devlop a novel sensor powered by the energy of the sensed signal itself.
So, well done to Alex and the group members. The awards committee unanimously thought this a particularly innovative discovery, which coincidentally falls squarely within the Sustainability Grand Challenge Theme.
We’ll be repeating the award next year so everyone please keep innovating!