Virtual microscope lens delivers a real revolution in imaging
A £4.3M EPSRC-funded project based at the University of Sheffield has produced the world's first lens-less microscope. With no technical limit to image accuracy or resolution, the technology is cheaper to produce than standard microscopes and is even able to 'see through' solid state devices such as microchips. The pioneering new technique could also have a number of applications in the Life Sciences, including cancer cell detection, imaging for biopsies and tissue engineering.
Professor John Rodenburg, of the Department of Electronic and Electrical Engineering at the University of Sheffield, has invented a process that can generate high definition images of an object without the need for the high quality lenses that account for a significant element of the cost of high-performance microscopes.
In a standard microscope, a lens is used to produce a magnified image, but the method still relies on the waves that make up the radiation (light, electrons or X-rays) interfering with one another to build up the image. With light, this is experimentally easy, but with very-short wavelength radiation (a fraction of an atomic diameter), the tiniest error in the lens or the experimental apparatus makes the waves interfere incorrectly, ruining the image. For this reason, a typical electron or X-ray microscope image is about one hundred times more blurred than the theoretical limit defined by the wavelength.
In order to by-pass this apparent impasse in lens-based microscopy, Professor Rodenburg and his team devised a novel technique to transfer the task of image formation from physical components (i.e. a lens) to a software algorithm – the Virtual Lens™. With his Virtual Lens™ software Professor Rodenburg was able to use a computer to effectively 'read' the diffraction pattern caused by the scattering of light from an object. Although this does not produce an image in the conventional sense, Professor Rodenburg discovered that the resultant diffraction patterns contain the information required to make up an image of the object, a process previously believed to be mathematically impossible to achieve. The revolutionary technique can also be used to measure a number of important properties, such as the thickness of a material.
The Virtual Lens™, which has received patent protection, is being implemented on existing electron or X-ray microscopes, to greatly enhance their imaging capability, but the technique promises to deliver more. Professor Rodenburg explains: "It is possible to contemplate a solid-state optical microscope, built into a single chip with no optical elements at all. All the weakness, difficulties and costs of lenses would be replaced by a combination of good quality detectors and computers. Ultimately we aim to be able to image any molecular structure in 3D".
Having established a spin-out company, Phase Focus, to apply the new technique to optical, X-ray and electron microscopes, the team are also exploring a number of other applications, including optometry (to produce breathable contact lenses) and a number of applications in the Life Sciences including cell biology, tissue engineering, tissue repair and regeneration and high throughput screening which is crucial to the detection and diagnosis of cancer cells. This last application could enable researchers to tailor drugs to suit particular individuals.
For further information, please contact Professor John Rodenburg at:
tel: 0114 222 5391
email : j.m.rodenburg@sheffield.ac.uk