What caught our attention outside the world of oil and gas this month
A team at the Deutsches Elektronen-Synchrotron (DESY) has developed a deposition method for custom-made magnetic sensors.
Magneto-resistive sensors are used extensively throughout many technologies, but the variety of these applications means that each sensor’s function needs to be individually tuned.
These sensors are made up of microscopic stacks of alternating magnetic and non-magnetic layers, each just a few nanometres thick. When an external magnetic field is applied to such a multilayer stack, the electrical resistance of the stack changes. However, the magnetic field strength at which the resistor switches is largely fixed.
Now, researchers at DESY have developed a procedure which allows them, for the first time, to take control of the magneto-resistive properties of multilayer sensor systems. Their method allows the field strength at which each individual magnetic layer in the minute stack switches to be precisely and flexibly adjusted. In addition, the preferential direction for the magnetisation of the individual layers, the so-called “easy axis”, can be in any chosen orientation.
As a result, a multitude of new sensor properties can be achieved by straightforward means. Sensors can now be tuned to their precise application, rather than the other way around.
The method uses a technique called oblique incidence deposition (OID). It enables arbitrary magnetic materials to be magnetically shaped on arbitrary substrates.
According to the team, “This means that it is now possible to straightforwardly produce structured multilayer stacks having identical compositions of materials and thicknesses but exhibiting very different and novel sensor characteristics.”
Researchers at the Australian National University have developed a new spray-on coating for waterproofing applications.
It is hoped that the coating could be used to prevent ice formation on aeroplanes or to protect boat hulls from corrosion.
The coating is based on the combination of two plastics, each with different characteristics. Together they form a coating which is both tough and flexible. The superhydrophobic coating is also transparent and extremely resistant to ultraviolet radiation. PhD student William Wong, from the Nanotechnology Research Laboratory at the ANU Research School of Engineering, explained: “It's like two interwoven fishing nets, made of different materials… The surface is a layer of nanoparticles, which water slides off as if it's on a hot barbecue.”
Lead researcher and head of the Nanotechnology Research Laboratory, Associate Professor Antonio Tricoli added: “The key innovation is that this transparent coating is able to stabilise very fragile nanomaterials resulting in ultra-durable nanotextures with numerous real-world applications.”
In addition, the team refined two production methods, both of which they claim are cheaper and easier than current processes.
One method uses a flame to generate the nanoparticle constituents of the material. For lower-temperature applications, the team dissolved the two components into a sprayable form.
“A lot of the functional coatings today are very weak, but we will be able to apply the same principles to make robust coatings that are, for example, anti-corrosive, self-cleaning or oil-repellent,” Tricoli said.
The advent of 3D printers and laser cutters has opened up a wealth of new opportunities for workshop fabrication and prototyping. However, the ability to produce more complex parts with tougher materials has stayed largely within the confines of larger CNC milling technology – until now.
This month saw the launch of Wazer, a Kickstarter project to bring affordable water jet cutting to desktops. While traditional water jet cutters have large footprints and are (typically) prohibitively expensive, Wazer is aimed at users with “a limited budget and minimal space.”
It also will not require a redesign of your workshop. The unit is powered by a standard electrical outlet and fed by a water source. It uses 80 mesh garnet abrasive for cutting which is fed into the machine via an internal hopper, and cuts at a rate of 0.33 pounds per minute. This is a lower-pressure and slower cutting rate than might be found in larger industrial cutters, but should be enough for the desktop applications envisioned by the team.
According to the company, the unit will still cut through most material, including steel, granite (up to 9.5mm) and polycarbonate (up to 12.7mm).
The price is persuasive too. Wazer’s site suggests that a standard unit will retail at around US$6,000, with the first batches shipped in August 2017.
A joint team from the UK’s University of Birmingham and China’s Harbin Institute of Technology has developed a method of producing composites which can self-heal at temperatures below freezing.
Some composites – already mainstays in aerospace and power engineering and increasingly finding their way into oil and gas – have long had proven self-healing qualities. In some more instances, these have shown healing efficiencies above 100%, indicating that the performance of the healed material can be even better than when it was first formed.
Yet these results have traditionally been achieved at higher temperatures, and healing had proved more difficult in below-freezing conditions.
Instead the team embedded three-dimensional hollow vessels – in this case carbon nanotubes – into the composite, allowing them to deliver and releasing healing agents. A porous conductive element was also included to provide internal heating and to defrost the material where needed.
Using this method, they achieved a healing efficiency of over 100% at temperatures of -60°C using a glass fibre-reinforced laminate.
According to their report, using a carbon nanotube sheet as the conductive layer the composite “was able to self-heal more effectively with an average recovery of 107.7% in fracture energy and 96.22% in peak load.” They report that the technique could be applied across a majority of self-healing composites.
University of Birmingham PhD student Yongjing Wang added: “Fibre-reinforced composites are popular due to them being both strong and lightweight, ideal for aircraft or satellites, but the risk of internal micro-cracks can cause catastrophic failure. These cracks are not only hard to detect, but also to repair, hence the need for the ability to self-heal.”
The minivan for mini vans
Mercedes-Benz Vans has announced a partnership with drone delivery start-up Starship Technologies.
The collaboration will see the automaker outfit a Sprinter van to be used as a “mothership” for eight autonomous delivery robots.
Starship intends to build a fleet of autonomous robots which can deliver goods in local areas in 15-30 minutes within a 2 to 3-mile (3.2 to 4.8-km) radius. The robots drive autonomously but are monitored by humans who can take over control at any time.
Its partnership with Mercedes is an expansion and refinement of this model. The larger vans will drive to a designated locations based on delivery density and demand, and then drop off and pick up robots which will complete the door-to-door deliveries. They will then return to the host van for re-loading.
An in-built racking system within the Sprinter enables 400 packages to be delivered every 9-hour shift, according to Starship. This compares with the 180 packages delivered using previously available methods, an increase of over 120%.
Mercedes-Benz Vans head Volker Mornhinweg commented: “We see a huge potential for robotic delivery systems in the future and by combining our vans and the robots – we call it the mothership concept. With this we are able to increase the efficiency of delivery by an order of magnitude.”