5-May-2017: First synthetic soft retina created for visually impaired
The first synthetic, soft tissue retina developed by Oxford University researchers could offer fresh hope to visually impaired people. Until now, artificial retinas have only been made from hard, rigid materials. The new research is the first to successfully use biological, synthetic tissues, developed in a laboratory environment. The study could revolutionise the bionic implant industry and the development of new, less invasive technologies that more closely resemble human body tissues, helping to treat degenerative eye conditions such as retinitis pigmentosa. Just as photography depends on camera pixels reacting to light, vision relies on the retina performing the same function.
The retina sits at the back of the human eye, and contains protein cells that convert light into electrical signals that travel through the nervous system, triggering a response from the brain, ultimately building a picture of the scene being viewed. Vanessa Restrepo-Schild led the team at Oxford University in the UK which developed the synthetic, double layered retina which closely mimics the natural human retinal process. The retina replica consists of soft water droplets (hydrogels) and biological cell membrane proteins. Designed like a camera, the cells act as pixels, detecting and reacting to light to create a grey scale image.
Unlike existing artificial retinal implants, the cell-cultures are created from natural, biodegradable materials and do not contain foreign bodies or living entities. The implant is less invasive than a mechanical devise, and is less likely to have an adverse reaction on the body.
The human eye is incredibly sensitive, which is why foreign bodies like metal retinal implants can be so damaging, leading to inflammation and/or scaring. But a biological synthetic implant is soft and water based, so much more friendly to the eye environment. At present the synthetic retina has only been tested in laboratory conditions, and researchers want to explore potential uses with living tissues. The next step is vital in demonstrating how the material performs as a bionic implant, researchers said.
They have filed a patent for the technology and the next phase of the work will see the Oxford team expand the replica’s function to include recognising different colours. Working with a much larger replica, the team will test the material’s ability to recognise different colours and potentially even shapes and symbols. Further research will expand to include animal testing and then a series of clinical trials in humans.
25-Apr-2017: Scientists develop a method to 3D-print conquers glass
Scientists have developed a novel way to 3D-print objects using glass, an advance that could be used to make very small optical components for complex computers.
Researchers from Karlsruhe Institute of Technology (KIT) in Germany mixed nanoparticles of high-purity quartz glass and a small quantity of liquid polymer and allowed the mixture to be cured by light at specific points — by means of stereolithography.
Stereolithography is a form of 3D-printing technology used for creating models, prototypes, patterns and production parts in a layer by layer fashion using photopolymerization, a process by which light causes chains of molecules to link, forming polymers. The material, which remains a liquid, is washed out in a solvent bath, leaving only the desired cured structure. The polymer still mixed in this glass structure is subsequently removed by heating.
A variety of 3D-printing techniques available so far have been used on polymers or metals, but rarely on glass. Where glass was processed into structures, for instance by melting and application by means of a nozzle, the surface turned out to be very rough, the material was porous and contained voids.
In this new method, the material of the piece manufactured is high-purity quartz glass with the respective chemical and physical properties. The glass structures show resolutions in the range of a few micrometres — one micrometre corresponding to one thousandth of a millimetre. However, the structures may have dimensions in the range of a few centimetres.
The 3D-printed glass can be used for many applications, including data technology. The next plus one generation of computers will use light, which requires complicated processor structures, 3D technology could be used, for instance, to make small, complex structures out of a large number of very small optical components of different orientations.
24-Apr-2017: Material tougher, more conductive than copper developed
Researchers have developed thin carbon nanotube (CNT) textiles that exhibit high electrical conductivity and a level of toughness about 50 times higher than copper films, currently being used in electronics.
The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics, including biological and structural health monitoring sensors. Aligned carbon nanotube sheets are suitable for a wide range of application spanning from the micro to the macro-scales.
Tough nano-architecture conductive textile made by capillary plicing of Carbon nanotubes. Beginning with catalyst deposited on a silicon oxide substrate, vertically aligned carbon nanotubes were synthesized via chemical vapour deposition in the form of parallel lines of 5 micrometer wide, 10 micrometre in length, and 20-60 micrometre in heights.
The new CNT textile, with simple flexible encapsulation in an elastomer matrix, can be used in smart textiles, smart skins and a variety of flexible electronics. Owing to their extremely high toughness, they represent an attractive material, which can replace thin metal films to enhance device reliability.