These days, computers are used to control all manner of things, from robot vacuum cleaners to windmills to space rockets. But in order for computers to be able to connect with the physical world, a link is needed between the digital bits-and-bytes inside the computer, and the analogue motions that we see when the robot vacuum cleaner is zooming across the room or when an enormous space rocket is landing softly on the ground. This link is called a digital-to-analogue converter: it takes a blocky virtual shape from inside the computer and remakes a smooth physical shape outside the computer. Now, remaking a shape is never perfect; the remade shape will never look exactly the way it was intended. The imperfections are very small in today?s equipment, but there are still cases where it is desirable to make them even smaller. One example is building things at an atomic scale, assembling an object by moving single atoms, or when adjusting the refraction of light in very precise optical equipment used to improve images made by large telescopes. The aim of the project can be understood as completely vanishing the distinction between digital and analogue, or virtual and real. The fundamental physical limit of this vanishing is known, and the closest you can get to this limit today is by very expensive and rare equipment utilising quantum mechanical effects in super-conducting materials (Josephson junctions). This project will use this known limit as the benchmark and attempt to approach it with ordinary semi-conductor technologies, that can produce cheap and abundant devices, making such exceptional capability available to a wide range of end users.
High-resolution motion control has a wide array of applications in science and industry: adaptive optics, semiconductor lithography, fabrication and inspection, laser interferometry, measurement science, and scanning probe microscopy for imaging and manipulation on an atomic scale. A limiting factor in advancing the capabilities of these technologies is the noise and distortion introduced by the digital-to-analogue converters (DACs); the physical interface to digital control algorithms. The best performing DAC available today achieves a resolution of 47 parts-per-million (15 effective number of bits). The Project manager has set the new state-of-the-art by building a DAC with a resolution more than 12 ppm (17 ENOB), demonstrating an ability to innovate in and contribute to a highly competitive and active area of engineering science. This project aims to develop methods for DACs enabling a resolution of 1 ppm at high speed and with low latency by way of control engineering: modelling, model-based control and dithering; with implementations using highly advanced semiconductor fabrication methods. This level of performance has never been achieved before and will define the new state-of-the-art. A semiconductor device with such capabilities will be a key enabling technology because it will allow mass-market availability of unprecedented performance; e.g. better accuracy and precision in measuring instruments or low-cost, high-throughput manipulation of atomic-scale structures. Today, analogue-digital conversion is ubiquitous — it is a key element in any system requiring a digital-physical interface. It constitutes a USD 3.5 billion market that is increasing 10-15% annually. Better linearity and higher resolution will benefit any systems using such conversion, and methods relating to analogue-digital conversion will also have major impact in switched-mode devices used for e.g. renewable energy production and distribution, or communications.