5X Lithium Sulfur Battery with a Gut Feeling

Bio-mimicry presents itself in aerodynamics, from the emulation of soaring bird’s wing shapes on sailplane’s surfaces to owl-feather-like trailing edges on wind turbines.  We don’t often think of biological equivalents in energy storage (your editor didn’t until now, at least).  But researchers at Cambridge University in England and the Beijing Institute of Technology in China have turned to the small intestine for their breakthrough in battery development.

Tiny cells lining the human intestine inspired these researchers to develop a prototype of a lithium-sulfur battery that they claim could have five times the energy density of conventional lithium-ion batteries.  Dr. Paul Coxon from Cambridge’s Department of Materials Science and Metallurgy says “This gets us a long way through the bottleneck which is preventing the development of better batteries.”

Is That You, Villi?

Structure of villi in the small intestine

Structure of villi in the small intestine

Villi in the gut help process food being digested, trapping nutrient particles in millions of tiny, “finger-like protrusions” which increase the absorbent surface area over which digestion takes place.  In batteries, surface area enables greater electrochemical reaction between anodes, cathodes and electrolytes.

Dr. Vasant Kumar and his Cambridge team created and tested a lightweight nanostructured material with tiny zinc-oxide wires, which they placed on the battery’s electrodes.  According to researchers, “This can trap fragments of the active material when they break off, keeping them electrochemically accessible and allowing the material to be reused.”  This prevents loss of active materials and increases the life span of the battery.

How This Works in a Lithium-Sulfur Battery

A typical lithium-ion battery is made of three separate components: an anode (negative electrode), a cathode (positive electrode) and an electrolyte in the middle. The most common materials for the anode and cathode are graphite and lithium cobalt oxide respectively, which both have layered structures. Positively-charged lithium ions move back and forth from the cathode, through the electrolyte and into the anode. Illustration: Futurism.com

A typical lithium-ion battery is made of three separate components: an anode (negative electrode), a cathode (positive electrode) and an electrolyte in the middle. The most common materials for the anode and cathode are graphite and lithium cobalt oxide respectively, which both have layered structures. Positively-charged lithium ions move back and forth from the cathode, through the electrolyte and into the anode. Illustration: Futurism.com

Different materials determine how much energy can be squeezed into the battery.  Carbon electrodes can take on six lithium ions per carbon atom.  Sulfur can take on many more, making the battery theoretically more energy dense.  At least five times more so, if we’re to believe the Cambridge/Beijing researchers.  That’s where there the electronic villi come into action.

Mimicking Our Inner Workings

During discharge, when we get the stored energy back as work, “The lithium and sulfur interact and the ring-like sulfur molecules transform into chain-like structures, known as a polysulfides. As the battery undergoes several charge-discharge cycles, bits of the polysulfide can go into the electrolyte, so that over time the battery gradually loses active material.”

To emulate the work villi do in the body, researchers “Have created a functional layer which lies on top of the cathode and fixes the active material to a conductive framework so the active material can be reused. The layer is made up of tiny, one-dimensional zinc oxide nanowires grown on a scaffold. The concept was trialled using commercially-available nickel foam for support. After successful results, the foam was replaced by a lightweight carbon fiber mat to reduce the battery’s overall weight.”

Study co-author Dr. Yingjun Liu explained, “Changing from stiff nickel foam to flexible carbon fiber mat makes the layer mimic the way small intestine works even further.”The high surface area exposed on the fingers and its strong chemical bond with the polysulfides allows the material to last longer, and increases the lifespan of the battery.

“This is the first time a chemically functional layer with a well-organised nano-architecture has been proposed to trap and reuse the dissolved active materials during battery charging and discharging,” said the study’s lead author Teng Zhao, a PhD student from the Department of Materials Science & Metallurgy. “By taking our inspiration from the natural world, we were able to come up with a solution that we hope will accelerate the development of next-generation batteries.”

Not So Fast

Alas, as with so many such developments, things done at laboratory scale sometimes take another decade to reach commercial reality.  Talk of Manhattan Project levels of investment and urgency never seem to gain ascendancy for peace-time endeavors.  Let’s hope this and similar efforts find willing investors.

See the researchers’ results in the October 26, 2016 edition of Advanced Functional Materials

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Gleaning the Forests for Jet Fuel

Three congresspeople flew on wood-waste fumes this week, aboard an Alaska Airlines Boeing 737-800 on its way from Seattle-Tacoma International Airport (SEATAC) to Washington, DC.  It was the first commercial flight to “to be powered by a blend of renewable jet fuel made from forest residuals.

20-percent alcohol-to-jet (ATJ) fuel made from forest waste goes into Washington, DC-bound 737-800

20-percent alcohol-to-jet (ATJ) fuel made from forest waste goes into Washington, DC-bound 737-800

Waste Products Replace Fossil Fuels

Alaska, Boeing, and SEATAC have partnered on including biofuels in the mix since early 2015, as reported here.  Later that year, United made flights out of Los Angeles International (LAX) using a blend of fossil-based jet fuel and biofuels made from farm and municipal waste.  Keeping waste out of landfills and producing a lower carbon-footprint fuel has several benefits.  In the case of forest waste, those branches, limbs and twigs that litter the forest floor after a timber harvest, cleaning that debris away lowers fire risk in the warm seasons and makes renewable isobutanol.

Developed through a five-year project led by Washington State University and the Northwest Advanced Renewables Alliance (NARA) initiative and the U. S. Department of Agriculture, the program is now nearing completion.  This first flight on the 1,080 gallons produced so far marks a practical demonstration of the fuel’s viability.

Funded with $39.6 million grant from the National Institute of Food and Agriculture (NIFA)  “To support research on biofuels and biochemical, foster regional supply chain coalitions, empower rural economic development and educate the public on the benefits of bioenergy,” the project comprises 32 member organizations from industry, academia and government laboratories.

Good Enough for Dignitaries

GreenAir quoted some distinguished passengers.  “Three members of the House of Representatives were on the flight, including Congresswoman Suzan DelBene. ‘This flight demonstrates that Washington state’s innovation economy is once again at the forefront of collaborative, transformative research by using material that would otherwise be discarded to create a new biofuel,’ she said. ‘We have a tremendous opportunity in our region to build a new green economy and find innovative solutions to address climate change for our health and future generations, as this project highlights.’”

“US Senator for Washington, Maria Cantwell: ‘The flight comes after years of investments to help the aviation biofuels industry take off. By creating these sustainable biofuels, we will revitalize our rural agriculture communities, foster economic growth, reduce greenhouse gas emissions and cur our dependence on foreign oil while growing our competitiveness in global markets.’”

NARA Executive Director Ralph Cavalieri said, “This flight is a tribute to all of our NARA partners, and especially to NIFA who supported our mission to facilitate the revolutionary development of biojet and bioproduct industries in the Pacific Northwest using forest residuals that would otherwise become waste products.”

Gevo CEO Pat Gruber added, “We are pleased that we had the opportunity to prove, through the NARA project, that cellulosic sugars from wood can be used to successfully make commercial jet fuel.”

Gevo lab workers in Englewood, Colorado test wood-based fuel

Gevo lab workers in Englewood, Colorado test wood-based fuel

 GreenAirOnline reports, “Alaska and Gevo have already partnered on commercial biofuel flights from Seattle to San Francisco and Washington DC in June this year that used a 20% Alcohol to Jet (ATJ) blend derived from sustainable non-edible field corn grown in South Dakota.”

Alaska Airlines Senior Vice President for Communications and External Relations, Joe Sprague, said the biofuel used on yesterday’s flight was “especially exciting since it is uniquely sourced from forest residuals in the Pacific Northwest.”

Obviously, one flight with 20-percent biofuel will not cure rising emissions, but “the airline said if it were able to replace 20% of its entire fuel supply at Seattle-Tacoma, it would reduce CO2 emissions by about 142,000 tons per year.”

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A 24-Volt Airplane Motor?

One of the big surprises in last month’s webinar hosted by the EAA and presented by Brian Carpenter of Rainbow Aviation Services/Adventure Aviation was the 24-Volt motor being developed for the EMG-6 ultralight motorglider.

EMG-6 in side view with electric powerplant - still Part 103 legal, according to Brian Carpenter

EMG-6 in side view with electric powerplant – still Part 103 legal, according to Brian Carpenter

High and Low Voltages

Many, if not most of the electric motors flying on existing craft are higher voltage units.  For sake of an off-handed definition, we’ll divide low and high at below and above 50 Volts, something OSHA delineates in its regulation 29 CFR 1910.303(g)(2)(i), which “generally requires “’live parts of electric equipment operating at 50 volts or more’ to be ‘guarded against accidental contact by use of approved cabinets or other forms of approved enclosures’ or by other specified means.”  In its explanation, the Occupational Safety and Health Administration “considers all voltages of 50 volts or above to be hazardous. Electric current, not voltage, passing through the human body causes injury….”

And it really doesn’t take much amperage to take a person to the next realm.  Electric chairs, for instance, pass voltages from 500 to 20,000 Volts through the condemned’s body, but at currents of only five to 20 Amperes.  Shockingly, “A current of 0.070 ampere causes heart problems and may be fatal.”  The lesson is that all electric devices need to be treated with caution and respect.

While high power in aircraft electric motors comes from a combination of high voltages and high amperages (multiply the two to get the kilowatt output of the motor), Roman Susnik and EMRAX provide three voltage levels with correspondingly varied amperages to suit motors to different applications.

The Emrax 228, for instance, can be ordered in high, medium and low voltage configurations.  The high-voltage version can handle up to 600 Volts at a maximum current of 240 Amps.  The low-voltage model can run on 24 to 150 Volts, but at 900 maximum Amps.  Because the resulting torque is so great from especially the low-voltage motors, they can swing large propellers at low RPMs while providing significant thrust.  Certainly the early demonstration of low-speed torque shows low noise and an undocumented level of thrust at 450 RPM.  Most Emrax motors don’t exceed 2,200 RPM at full power.

A 48-Volt Automobile

A European car manufacturer, NanoFlowCell, produces two vehicles, the Quant F and Quantino, powered by liquid flow cell batteries.  The Quantino has four wheel-hub type 48-Volt motors, each capable of producing 200 Newton-meters (147.5 foot-pounds) of maximum torque.  We’ve covered the Quant in an earlier post.

This 48-Volt car ran 14 hours on a very level, smooth floor and still had 78-percent of the energy stored in its two 159-liter (84 gallons) tanks available, according to the company.  This demonstration, while impressive, is somewhat like Sanyo’s battery-powered six-year-old, 1,000 kilometer run without a recharge.  Run at 25 mph, Sanyo’s record was not a big challenge for even the draggiest vehicle.  It’s unlikely the Quantino went much faster, considering the confined quarters.

Salt water weighs about 8.5 pounds per gallon, so the Quantino is lugging around 714 pounds of motive power.  It has the same issue that batteries have, not diminishing in weight as the energy burns off.  Any car or airplane using either energy storage medium ends its journey as heavy as when it started.

48-Volt systems are becoming common in so-called “mild” hybrids with stop-start capabilities, but coming into their own as full-time powerplants for electric vehicles.  Beyond that NanoFlowCell warns of the “spectre” high-voltage dangers.

A 24-Volt Airplane Motor

Brian Carpenter has tried several electric motors on his EMG-6 motorglider, and is planning the first runs for the R&D motor developed in collaboration with that company.  The 24-Volt motor would turn a big propeller slowly, just as the Polini two-stroke also tested on the airplane manages.  A large, slow propeller is great for quick climbs to gliding altitude, and a battery pack can then be used intermittently to search for thermals or assure a return to the field.

Collaborating with Ed Donovan at R&D Cable, Brian describes the prototype motor as a good alternative to two-strokes, even borrowing small parts from them.  “The bolt pattern is the standard two-stroke Rotax engine bolt pattern. the bearing is the same as the front bearing on the Rotax E gearbox. The total motor weight will be in the neighborhood of 25 pounds when completed. There are 6 mounting locations on the rear of the motor housing. During testing at full power the outer housing gets slightly warm but the windings and the magnets remain cool even at full power operation. They are still undergoing some operational tests on the motor and perfecting the final design before going into the mass production phase and developing the tooling for the stamping dies for the winding core. The expectations are that the efficiency of the motor will exceed 95%. And reliability and durability are key components in the development of the motor. I would expect that this motor will have a TBO in excess of 10,000 hours. And overhaul cost will be the replacement of 2 bearings. We have been told that we should expect to have an operational motor available for installation before we depart for the Oshkosh airshow.”

Brian Carpenter mounting R&D motor. Note wide blades on 48-inch propeller, Alternative three-blade Sterna propeller is also under test

Brian Carpenter mounting R&D motor. Note wide blades on 48-inch propeller, Alternative three-blade Sterna propeller is also under test

If the high-torque ability to swing a propeller slowly in a high=thrust way turns out to combine the (relative) safety of low voltage with the ability to scramble for altitude, this may move more designers to opt for the low-voltage option.

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China has over one billion, four hundred million people.  Slovenia has a little over two million.  This population disparity has not kept Pipistrel d.o.o. Ajdovscina and Chinese company Sino GA Group Co. from signing a Memorandum of Understanding for a long-term joint-venture in the field of light and general aviation in the regions of China, East Asian countries and the Asian Pacific region.

Pipistrel will built 50 each of their Panthera hybrid cruiser and 50 each of their Alpha Electro Trainer as part of the cooperative package

Pipistrel will built 50 each of their Panthera hybrid cruiser and 50 each of their Alpha Electro Trainer as part of the cooperative package.  Eventually, 500 aircraft per year will be produced in China

Pipistrel, led by General Manager Ivo Boscarol, has built many airplanes in its 27-year history (including over 800 of its Sinus/Virus series), and earned plaudits for its clean manufacturing and ethical management.  It has led in development of electric motorgliders, an electric training aircraft, and a high-performance hybrid cruiser.  It won the Green Flight Challenge in 2011 with a battery powered aircraft that managed to cruise at over 100 mph for 200 miles and returned 403.5 passenger miles per gallon.  That airframe has been converted to hydrogen power and was flown in September in a 10-minute demonstration at Stuttgart Airport.

Rather than keeping electric aircraft as precious rarities with distant future, The MOU will lead to production of as many as 500 new electric and hybrid aircraft per year in China, a significant increase in environmentally-friendly flight (and a big number in General Aviation, period.)

This is a big win for Pipistrel, an efficient operation with 87 employees working in a leading edge factory that relies on clean, renewable energy to produce green aircraft.  Expect to see lots of visitors and trainees swelling their ranks in the next few months as Sino GA personnel learn the procedures for producing the Alpha Electro light trainer and the Panthera hybrid four-seater.

Ivo Boscarol signs for Pipistrel, Wu Guo Ying signs for Sino GA Group Co.

Ivo Boscarol signs for Pipistrel, Wu Guo Ying signs for Sino GA Group Co.

Pipistrel employees will be in China, too, helping establish manufacturing and overseeing quality control to assure Slovenian and Chinese aircraft are equally capable.  Operations in China will include work with the Sino Group and a subsidiary, Flying Tigers (Beijing) General Aviation Co., Ltd., which among other things operates airports and bases in Beijing, Taizhou, Yinchuan, Huangping, Dalian and Heibei.

Plans include using Pipistrel’s recent experience with Germany’s DLR to create the first hydrogen four-seater, the HY4, from the Green Flight Challenge winning G4.  The cooperative group looks forward to designing and launching a larger craft with potentially international application.  With the agreement providing up to 350 million euros (about $385 million) in its initial phases, such R&D will be possible, and with Pipistel’s visionary approach, productive.

The cooperative describes the airplane as a, “new, very innovative zero emission 19-seat aircraft, powered by hybrid electric technology and hydrogen low temperature PEM fuel cells, planned for public transport between the cities in China and all over the world.

Pipistrel’s press release shows two major international events at which the MOU will be featured:

European/Asian economic summit meeting at which cooperative was announced

European/Asian economic summit meeting at which cooperative was announced

“Official presentation of the cooperation will be held on  2nd November 2016 at 10:00 AM, at the China International Aviation & Aerospace Exhibition in Zhu Hai, the  biggest Air show in China where at the booth of Sino Group & Flying tigers, the General distributor of Pipistrel for China,  three Pipistrel aircraft are displayed.

“The formal contract signing ceremony will be included in the framework of the upcoming Summit side event on 5th November 2016 at the Prime Ministers of China and Central and Eastern European Countries summit 16 + 1 in Riga, Latvia, as it is ranked among those of particular significance for bilateral [cooperation] between the two countries.”

With Pipistel’s growing influence on world aviation, such agreements may become more widespread, with partners contributing to the increasing growth of green aviation.

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Equator P2 Runs Up Its Motor

The Equator P2 is a hybrid amphibious two-seater that looks like the future.  Under development for a decade, this amateur-built machine looks highly professional, surpassing in form and function many of its factory-built peers.  It had its first motor run-up recently, a much-anticipated event that met all expectations.

One can see the garage-built home of the craft in the simple bracing used to hold the tail-mounted motor in place, an example of the truly hand-made nature of the Equator prototype.  The rudimentary surroundings fail to show the sophistication of the design, however, including a power system similar to that used on the range-extended e-Genius.

Progress over the last nine years has been limited, as with many such projects, by (in Tine Tomazic’s words)”the speed of cash.”  As with other such projects, the family car occupies the driveway, the Equator the garage.

Tomas Brodreskift designed the craft while serving an internship with Airbus.  He spent spare moments visiting Guenter Poeschel, designer and builder of three large Equator aircraft, including one amphibian with its engine mounted on a tall mast.  The other two craft featured an engine on a nacelle protruding from the leading edge of the vertical fin.

Industrial and Aeronautical Design Meet Harmoniously

According to the Equator web site, “Tomas Brodreskift met Guenter Poeschel in Southern Germany whilst doing an Internship with Airbus / Diehl Aircabin in 2008. Visiting often and learning about the amazing aircraft that were developed was inspiring, and he decided to take the P2 (the smallest concept) back to Norway and develop it further with partner Oeyvind Berven.”

Equator P2's low-pilot-workload cockpit

Equator P2’s low-pilot-workload cockpit

In that time, Tomas has used his industrial design skills to create a roomy cabin, expandable two-plus-two capacity, with pilot and passenger under a clear dome and facing a simple glass cockpit and controlling things through a fly-by-wire system with no rudder pedals, all coordination being taken care of by software.  Pilots will find a lower workload with a single control lever managing a complex network of Diesel generator, batteries, motor controller and motor to create thrust from the tail-mounted propeller.  It is similar to the range extender package recently tested on e-Genius.

The video shows progress up to the airplane’s debut at AirVenture 2013, and highlights the range of skills required to create such a craft.

As your editor reported in the Kitplanes Newsline, Tomas follows a four-part mantra in defining his design:”Automation, Efficiency, Usability, Sustainability. Automation applies computers to simplify user interaction, and the careful design enables efficiency and lower power requirements. Usability comes in the large cabin, able to haul long and large objects such as bicycles and skis and even allow overnight camping – a true bush plane. Sustainability comes from the hybrid power system, designed to use low-cost biofuels and ‘have no impact on the environment in a bad way.’”

Following a long development and construction period, the Equator P2 may be on the verge of full-systems testing and initial flights.  We look forward to new developments from this dedicated designer and his team.

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Larry Page’s Flying Car(s)?

A3 backed by Airbus, EHang 184 from China, and Zee from Larry Page (head of Google) – Silicon Valley seems an unlikely source of aeronautical breakthroughs, but several entrepreneurial outings from Airbus, Chinese startups, and Zee.Aero, led by a secretive Larry Page, have interest growing.  A pair of recent flights by Zee’s craft in Hollister, California have generated coverage – and speculation.

Larry Page’s Two Companies

It turns out Page has a second company, Kitty Hawk, taking yet another path toward electrified flying cars with something like a large quadcopter – not unlike the eHang 184.  Neither Zee.Aero nor Kitty Hawk is affiliated with Google, both funded out of Page’s largesse.  One theory is that his two companies, the first started by noted aerodynamicist Ilan Kroo and the second headed by Sebastian Thrun, will engage in a friendly competition to create the best device for future development.

Sharing these videos and pictures with friends has resulted in varying degrees of problems in identifying the craft as the vehicle shown in Zee’s patent drawings.  Mary Grady of AVweb reports “The aircraft, seen in photos published online by the Monterey Herald, appears to be based on a Tecnam fuselage, with an array of small propellers mounted on booms in front of and behind the wing, and a pusher prop mounted beneath the tail. A knowledgeable source who spoke to AVweb today on condition of anonymity confirmed that the aircraft in the photos is Zee.Aero’s latest model.

Artist's concept of Zee.Aero aircraft, based apparently on patent drawings. Actual craft in Hollister has fuller depth to fuselage

Artist’s concept of Zee.Aero aircraft, based apparently on patent drawings. Actual craft in Hollister has fuller depth to fuselage

The compression that comes from long telephoto lens shots of the machine makes positive analysis of features on the craft difficult.  Certainly, the fuller depth of the fuselage looks like the Tecnam fuselage (also used on NASA’s X-57 test vehicle).  Eyewitness accounts, though, emphasize the quietness of the machine during its two brief hovers.  That is one of the requirements for finding acceptance in neighborhood airparks.

With Oliver Garrow having also made test flights with his Elytron test bed at Hollister, the site may become the Skunkworks for future urban aerial transport.  We hope to see the fruition of many talented efforts coming our way soon.

A Brief History with one Bullish Accomplishment

Zee personnel have already set one record for personal flight, although not one the average commuter will embrace enthusiastically.  The team’s 2013 Red Bull Flugtag entry did set a record for distance, but probably did not get the team invited to Dancing with the Stars.

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Making Silicon Anodes in Large Batches

A Long-term Collaboration

Dr. Jaephil Cho is a well-known battery researcher and inter-continental associate of Dr. Yi Cui of Stanford University.  The pair has collaborated on many ways to improve battery performance and longevity, and both have appeared at various electric aircraft symposia.  They have even inspired others in related research. Dr. Cho and his team at Ulsan National Institute of Science and Technology (UNIST) in South Korea announced a way to make a new generation battery anode material – a big move toward mass production of improved cells.

Dr. Cho’s team of researchers affiliated with Ulsan National Institute of Science and Technology (UNIST), South Korea, claims to have made yet another step towards finding a solution to accelerate the commercialization of silicon anodes for Lithium-ion batteries.

A Next-generation Hybrid Anode

As reported by UNIST, “Prof. Cho and his research team have developed a new type anode material that would be used in place of a conventional graphite anode, which they claim will lead to lighter and longer-lasting batteries for everything from personal devices to electric vehicles.”

While many of Dr. Cui's batteries and components look like various fruits, Dr. Cho's looks more like a malted milk ball (editor's perspective)

While many of Dr. Cui’s batteries and components look like various fruits, Dr. Cho’s looks more like a malted milk ball (editor’s perspective)

A next-generation hybrid anode using silicon-nanolayer-embedded graphite/carbon suffered many of the problems associated with the use of silicon as an active material in batteries. The material is great at soaking in lithium during charging, and releasing it during discharge.  This repeated expansion and contraction of the silicon causes it to crumble over time, diminishing and finally destroying the battery’s performance.  Such structural failures occur with silicon particles made by conventional mechanical milling.

Drs. Cui and Cho have developed various approaches that ended up looking like fruits or other organic materials, copying nature in their structure.  Interestingly, this structure looks more like a malted milk ball to your editor.

660 Pounds in Six Hours

A newly-developed anode material has been manufactured with an increase in graphite content in composite by 45 percent. The research team even developed new equipment capable of producing 300 kilograms (660 pounds) in six hours per batch using a small amount of silane gas (SiH4), a simple procedure expected to ensure a competitive price.  Industrial-size outputs at this stage of development seem to show a clear path to commercialization.

According to UNIST, “They report that the silicon/graphite composite is mass-producible and it has superior battery performances with industrial electrode density, high areal capacity, and low amounts of binder.”

This work has been supported by the IT R&D program of the Ministry of Trade, Industry & Energy (MOTIE) and Korea Evaluation Institute of Industrial Technology (KEIT), 2016 Research Fund of UNIST, and by the Office of Vehicle Technologies, Battery Materials Research Program of the US Department of Energy.

Minseong Ko, Sujong Chae, Jiyoung Ma, Namhyung Kim, Hyun-Wook Lee, Yi Cui, and Jaephil Cho published “Scalable synthesis of silicon-nanolayer-embedded graphite for high-energy lithium-ion batteries,” in the August, 2016 issue of Nature Energy.

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Brammo, one of the first American electric motorcycle makers, established itself as an early competitor in racing, and after less than a decade in the new arena, sold the motorcycle racing enterprise to Polaris Industries Inc.  “Following that announcement, Brammo confirms its exclusive agreement to supply its electric powertrains to Polaris for inclusion in motorcycles and other on-road and off-road vehicles.”range of vehicle OEMs.”

From Motorcycles to Helicopters

Surprisingly, that range of vehicle OEMs includes a successful electric helicopter launch.

According to the Portland Business Journal, “Brammo lent its expertise to a Tier 1 Engineering launch of a battery-powered manned helicopter last month. The launch included the first hover taxi and a record five-minute cruise flight to 400 feet altitude.”

Dual motors allow flight even if one fails

Dual motors allow flight even if one fails

Tier 1 describes itself as “A provider of engineering services, specializing in lightweight composite structures. We offer engineering design and build services to the Aerospace, Energy, Marine, Medical, and Consumer Product sectors. We handle all projects in a secure environment to protect client privacy and follow AS9100-compliant quality practices.”

Teir 1’s President Glen Dromgoole, reports the September 21 flight at Los Alamitos Army Airfield in California, included a vertical takeoff, cruise and landing based solely on battery power.”

Brammo's 1,100-pound battery pack contributes to 2,500 pound gross weight

Brammo’s 1,100-pound battery pack contributes to 2,500 pound gross weight

Brammo contributed 1,100 pounds of lithium polymer batteries (approximately the weight of a Tesla S battery pack) to the effort, which included twin electric motors and a control system from Rinehart Motion Systems.

The craft flew for five minutes on an oval course around the field, and landed with about 80-percent of the pack’s energy remaining.  It will be interesting to see future flights with greater altitudes and/or endurance.

Tier 1 reports, “Lung Biotechnology PBC intends to apply the EPSAROD technology to distributing manufactured organs for transplantation to major hospitals with much less noise and carbon footprint than current technology.  Tier 1 Engineering is an aircraft design and development company with operations in Costa Mesa, California, and Victoria, Australia.”

Previous Attempt

In 2010, Sikorsky showed an electric Firefly™, a battery-powered S-3000 which swapped the original gasoline engine for an electric motor and two 45-kilowatt-hour Lithium Technology Corporation Gaia battery packs.  These were intended to power a 190-horsepower electric motor, but it’s unsure whether the helicopter ever flew under battery power.

Tier1’s Specifications and Potential

The converted Robertson R44 helicopter has a gross weight of 2,500 pounds, complete with a Brammo battery pack weighing 1,100 pounds.  Although unchanged from a standard R44, the craft has a digital cockpit display to allow pilot management of torque and power.  It also provides data logging.

The machine has an estimated endurance of 20 minutes, or approximately 30 nautical miles of range.  As with all such projects, the developers hope to obtain higher energy density batteries.  A nine-person team took six months to bring the craft to its present state, removed the original Lycoming IO-540 engine, and replaced it with two electric motors and a reduction gearbox in a custom installation, and devised a large, under-aircraft mount for the 11 battery modules.

Although the term “semi-autonomous” appears in the acronym “EPSAROD,” there are no such features in the current version.  “The purpose of the aircraft is to demonstrate the feasibility of battery-powered VTOL and cruise for a manned helicopter.  Semi-autonomous avionics, navigation and controls will be implemented later in the EPSAROD development program. The ultimate goal of the EPSAROD Program is to produce electric-powered semi-autonomous aircraft that are capable of distributing manufactured organs to hospitals for transplantation,” according to Tier1.

Eventually, with better batteries, of course, the helicopter could carry two people and three“manufactured organs with a total payload weight of 600 pounds for not less than 150 minutes, including a 30-minute reserve.”

Look for ongoing flight tests and a more advanced vehicle due in late 2017.

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Outback Joe goes through a lot of trauma in his overstuffed life.  This literal straw man gets tossed into some remote part of the Australian outback every year and waits for some kind of rescue.  This usually comes by air, drones searching for him and taking him medicine, food, water, or some other necessity.  That’s the Outback Challenge.

UAV Challenge teams for 2016, showing a wide (wild) range of configurations

UAV Challenge teams for 2016, showing a wide (wild) range of configurations

One can see a condensed history of the competition from its inception in 2007 to today on Wikipedia, the entry including the different kinds of things Outback Joe needed for a mission to be successful.

This year, however, competitors were supposed to bring back a reminder of their visit to Joe – a blood sample – a good trick from an inanimate being who might answer to “Hay!”

Outback Joe in typically relaxed pose, awaiting delivery of life-saving materials. This is from 2014 contest

Outback Joe in typically relaxed pose, awaiting delivery of life-saving materials. This is from 2014 contest

Richard Glassock, now a Research Fellow at the Institute for Aerospace Technology, the University of Nottingham, describes the vision and how it has grown up.

“The competition Rod Walker and I first discussed about 16 years ago has matured into something really worthwhile. We ran the first one in 2007, and the most recent event realizes much of the initial vision. Originally I wanted to deliver pizza and beer, but the medical emergency rescue theme is clearly of more immediate value.”

According to DroneMagazine.com, ten teams qualified for the event:

  • CanberraUAV (Australia) West Coast UAV (Australia)
  • UNSW Canberra UAV Team (Australia)
  • Monash Unmanned Aerial Systems (Australia)
  • PerthUAV (Australia)
  • Forward Robotics (Canada)
  • MelAvio (Poland)
  • ArsNumerika-JetStream (Poland)
  • MAVLab TU Delft (The Netherlands)
  • ISAAC UAV, Kasetsart University (Thailand)
  • Airborne Delivery Challenge

Day One

Richard reported on the progress for the event, with Day One devoted to scrutineering the ten entries, assuring that all participants met the requirements for the event.  The Ars Numerica entry from Poland, the Jet Stream, was held up in customs and passed technical review the next day.

Following are three videos of the checks necessary to assure smooth running (fate aside) for a successful Outback run.  The first shows the Canberra effort, the second the Monash, and the third the Polish JetStream.  All are serious machines with extremely smooth control when left to their own autonomous ways.

Day Two

Seven teams made the retrieval attempt (out of the eight that made it through tech review). Richard summarizes Day Two here: “There is one more day to run, but so far it appears Canberra UAV has again led the field by utilizing a Quadrotor Fixed Wing VTOL to fly the cross country mission, autonomously land, and return with the medical payload. I have always considered this to be a most viable and versatile configuration. They would have fully completed the mission and collected the $50k prize money again this year, had their relay communications platform not suffered an engine failure. The gas powered helicopter had to make an autorotation forced landing. Perhaps a hybrid-electric powerplant would have provided the necessary power and endurance while giving sufficient redundancy to complete the mission? In any case, it was an excellent and successful result overall demonstrating the utility of these systems for real world humanitarian applications.”

ISAAC UAV of Kasetsart University from Thailand fielded a helicopter, which unfortunately began smoking just after spotting Joe, and suffered damage in a heavy landing.

Two Perth, Australia teams came afoul of the geofencing that marked aerial boundaries, and flying outside the lines disqualified one of them.

Delft Technical University’s Delftacopter – which the team described as a “Delta-wing Electric Longrange Transitioning Autonomous Helicopter” showed great promise, looking a great deal like JoeBen Bevirt’s power kite systems of five years ago.  Fate intervened during a good run, though, and Delftacopter was snared in a very tall tree.

Competitors could use a kind of “tag team” approach, fielding one craft as a spotter and the other to retrieve Joe’s sample.  Monash University had a helicopter to speedily find Joe, but that lost power and autorated to a punishing landing.

Day Three and Results

UAV Challenge final scores. See UAV Challenge web site for details https://uavchallenge.org/

UAV Challenge final scores. See UAV Challenge web site for details

The UAV Challenge site reports on the final day.  “Canberra UAV were clearly first on points but did not complete the Challenge as their support aircraft crashed at the farm. But they did return the blood sample and this was a massive achievement and something that the organizers had not expected in the first running of the Medical Express event. Congratulations to them.”

Delft had perhaps the most dangerous part of the mission, retrieving their aircraft from that very tall tree.  “MAVLab TUDelft came second using their very new type of aircraft – the Delftacopter. They even managed to recover it from the very high tree at the end of the flying day yesterday, and so they were quite happy.”

The High School Airborne Delivery Challenge

A related event, the Airborne Delivery Challenge, open to high school teams, had a good number of entries and a variety of innovative approaches.

Palmdale High School students won the Delivery Challenge

Knight High School students from Palmdale, California won the Delivery Challenge

According to the organizers, “Phantom Soldiers, a team from the Knight High School in Palmdale, California, has won the 2016 Airborne Delivery Challenge and $5,000. It was a great contest but the accuracy of Phantom Soldiers’ drops was incredible and they won by more than 10 points. All three of their medical packages also landed next to Outback Joe with an impact force under 75G (the requirement to gain maximum points). It seems that their innovative drop mechanism and packaging were one of the secrets of their success.”

The level of creativity and competitiveness shows the ongoing progress in airframe design, sometimes complex power design, and a growing capability of autonomous controls.  It might be only a few Outback Challenges away before we see Joe airlifted to safety, while enjoying a slice of pizza and a pint of Foster’s Lager.

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Brian Carpenter’s EMG-6 Webinar

Brian Carpenter, designer of the EMG-6 motorglider which he’s shown over the last several years at AirVenture, will stage a webinar to discuss “the design and development concepts of this new electric motorglider.”  His talk will have special “Emphasis on the integration of the electric propulsion concepts that he believes will change the face of the light aircraft and ultralight industry.”

EMG-6 with R&D motor in place

EMG-6 with R&D motor in place

Your editor has visited Brian’s Corning, California workshop several times, and always found new and innovative approaches to producing a low-cost, self-launching motorglider, with several ways to simplify construction and to power the craft.  It will be interesting to see progress on the newest motor (apparently still under development) Brian has presented on his web site.

Hydroformed rib with EAA-approved embellishment

Hydroformed rib with EAA-approved embellishment

He has been experimenting with low-budget hydroforming for making repeated metal parts and making plastic parts using 3-D printers.  His shop is always worth seeing.

To register for the session, click here.

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