Dr. Yeuh-Lin Loo, an Assistant Professor in Chemical Engineering, has led a team of Princeton, University of Texas – Austin, Pennsylvania State University, University of California – Santa Barbara, and Dupont researchers in developing a conductive plastic that takes the place of expensive indium tin oxide (ITO) used in solar cells, flat-screen TVs, and other electronic devices with display screens. ITO, a byproduct of mining, is rare and expensive, but a necessity in today’s electronics. An inexpensive substitute would be desirable in bringing costs down and removing pressure from the growing demand for ITO. Loo comments on this in the Princeton press release. “The cost of indium tin oxide is skyrocketing. To bring down the costs of plastic solar cells, we need to find a replacement for ITO. Our conducting plastics allow sunlight to pass through them, making them a viable alternative.” ITO has the characteristic of allowing sunlight to pass through its transparent structure, enabling its collection and conversion …
Silicon Alloy Anode Yields 30-Percent More Capacity
Just for notebook computers now, enough of these -as in the over 6,000 such cells that propel a Tesla, could have a profound short-term effect on our hopes for electric flight. The 18650 (18 mm in diameter, 65 mm long) cells by Panasonic are the first to offer a silicon alloy anode, a commercial verification of the research Drs. Cui and Cho have been performing. Panasonic promises 4.0 Amp hours capacity, almost 30-percent more than current lithium cells of the same size. This allows a notebook battery pack almost half the size of one using graphite anode cells. The good news is balanced by the fact that the Si-based cell, at 54 grams each, weighs 10 grams more than the existing model. According to Nikkei Electronics Asia, “The initial target application will be notebook PCs, but a source at the firm comments ‘the ultimate target is vehicles.’ For vehicular applications, weight will be a key issue…. The weight energy density …
Overcome Inertia, Read About Enertia
David Bettencourt, an eagle-eyed legal eagle in Hawaii, prompted me to pick up a copy of the April, 2010 Cycle World magazine, in which two articles advance the cause of electric transport. The first,”Brammo Enertia”, is a critique of the electric cycle that you can buy at Best Buy. It details the long-term interest of company founder Craig Bramscher in electric vehicles, and his analysis that a vehicle with sufficient range for today’s suburbanite, based on normal commuting needs and available technology, would have two wheels – hence the Enertia. Matthew Miles, author of the piece, does a good job of comparing performance with a 250-cc Kawasaki Ninja. Although the Enertia is no match for the IC-powered machine in off-the-line sprints or top speed, it wins the economy-of-operation cup. (Cycle World’s web site has the added bonus of an interview with Craig Bramscher.) The second article, “Batteries Heat Up” is by Bettencourt’s favorite technical writer, Kevin Cameron. It’s easy to see why Bettencourt collects Cameron’s articles, since …
Trikebuggy Addendum
In “Two Motors and Everything But Coffee,” our entry for February 28, we detailed Pierre-Jean Beney’s Hacker motor-powered Trikebuggy. Pierre-Jean wants to change things, including, “The motor, the prop, the battery and the wing… So I am still somewhat away from where I want to have….” Currently, it takes 2,000 propeller revolutions per minute to maintain level flight. The LiF2PO4 batteries allow a current draw of 160 Amps at 48 Volts, and will produce level flight power for about 22 minutes at this rate. These are, according to Pierre-Jean, very safe batteries, but heavy. Pierre-Jean’s new batteries are Li-Po, which will give 52 Volts at the same amperage, but are, in his estimation, less safe. They are also lighter, weighing only 6.6 kilograms (about 14.5 pounds), and have lower internal resistance. The pictures below show the relative size of the old and new batteries. You can follow Pierre-Jean’s experiments on the Trikebuggy Owners’ Yahoo Group and see additional photos of his and other Trikebuggies.
Cutting Grass with Manfred Ruhmer
Manfred Ruhmer has designed a motorized trike for the Laminar wing under which he has flown to world champion status three times, and achieved a world record flight of 701 kilometers (434.62 miles). The trike can be powered with a Simonini two-stroke or Bailey four-stroke engine, or the Geiger/Eck electric motor/controller/folding propeller combination. Here, Manfred shows off some of his world-class flying skills. Note that about 40 seconds into the video, the landing gear has picked up some vegetation. Later, at around the 2:00 mark, the streamers reappear. Whether this is from the grassy field from which Manfred flies, or some very low passes, is open to speculation. The Icaro 2000 site is useful for making some important comparisons between the IC engine options and the electric flyer. Each of the two engines’ installed weights is 18.3 kilograms (40.26 pounds), and the fuel tank for either holds 8 liters of fuel. Icaro claims both engines consume about 2 to 2.5 liters per hour, giving up …
EAS IV is Your Ticket to an Electric Aircraft Future
This press release from the CAFE Foundation speaks for itself. The fourth symposium of its kind is an international, multidiscipline gathering which will influence the very future of aviation. Santa Rosa, CA., Mar. 1, 2010 – The Comparative Aircraft Flight Efficiency (CAFE) Foundation’s 4th Annual Electric Aircraft Symposium (EAS IV) will convene a renowned faculty of experts on electric aircraft technologies on April 23-24, 2010, at the Doubletree Inn in Rohnert Park, California. The networking program will consist of presentations and exhibits on bio-fuel hybrids, advanced electric motors, solar panels, sailplane technology, fuel cells, future technology for batteries, battery safety during charging, propeller noise reduction, autonomous flight controls, drag reduction, vertical takeoff designs and NASA’s Green Flight Challenge competition. Each presentation will be followed by a Q&A session with the audience, which will be comprised of government officials, enthusiasts, designers, entrepreneurs, students and media. The debut of some exciting new designs is expected at this year’s meeting. Among the outstanding …
A Manned Swift Takes Flight
Dr. Steve Morris is President of MLB Co., an enterprise specializing in low-cost, compact, remotely piloted and autonomous aerial surveillance, mapping and monitoring systems. On December 23, 2009, he and his associates test flew their first man-carrying, directly-piloted craft – an electric one. Pilot Brian Porter made two flights totalling about 20 minutes in a part 103 ultralight Swift hang glider to which was attached a custom-built pilot/powerplant/landing gear module. Power was by a Randall Fisher-supplied ElectraFlyer motor coupled to a reduction system built by Dr. Morris and his associates at MLB. Despite limitation imposed by the motor controller’s maximum current and propeller efficiency limited to 65-75 percent, the airplane demonstrated performance within 10 percent of calculations. Its rate of climb was 335 feet per minute, maximum level flight speed was 60 miles per hour, and it cruised on 4.6 kW. Duration, range, rate of climb, and lift:drag are expected to improve when a pilot fairing streamlines the very open cockpit on the current version. Dr. Morris will present his …
Two Motors and Everything but Coffee
Pierre-Jean Beney may be the first to fly an electrically-powered paraglider with a tricycle wheeled chassis. Using a Trikebuggy, itself a unique platform, Beney mounted two Hacker A200-8 motors with 220 Amp controllers, a tidy reduction system, and his own microprocessor board to drive the motors with a combined throttle and kill switch. The board, according to Beney, also monitors the LiF2PO4 batteries, RPM, and will soon be connected to a global positioning system (GPS) to measure speed, “and eventually make coffee!!!” Other anticipated changes may include different motors, including a larger, direct drive type. The motors are each capable of producing 15 kW and can handle 185 Amps of current continuously, with 300 Amps peak. Beney provided your editor with a brief tutorial on the difference between powered paragliders (PPG) and powered parachutes (PPC). “This is not a powered parachute, it is a powered paraglider (you can tell by the shape of the wing which is very rounded compared …
Doing More With Much, Much Less
This dictum from Paul MacCready that we can do a great deal more with far less material expenditure is well realized in a big way by researchers at the California Institute of Technology (Caltech) with their new type of solar cell. Using about two percent of the silicon semiconductor material normally required for crystalline cells, and achieving a high level of energy conversion, the new cells may also be relatively inexpensive to manufacture. As noted by Harry Atwater in Caltech’s press release, “These solar cells have, for the first time, surpassed the conventional light-trapping limit for absorbing materials…” Atwater is Howard Hughes Professor, professor of applied physics and materials science, and director of Caltech’s Resnick Institute, which according to the press release, “focuses on sustainability research.” Arranged like rug fibers in a vertically-oriented array, the individual silicon wire solar cells comprise a small portion of the total horizontal area of the cell, the rest being an inexpensive polymer substrate. Atwater …
Give Up Smoking Today, Get Better Mileage
Critics of biofuels often cite the contrary use of foodstocks for producing ethanol, for instance, as a process that will lead to food shortages, and consequently higher prices for fuel and food. One researcher and his graduate students are investigating a way to convert waste such as orange peels and old newspapers, and social and health irritants such as tobacco plants, and turn them into a cheap, clean fuel. Dr. Henry Daniell is head of the Biotechnology Graduate Program forthe Burnett School of Biomedical Sciences at the University of Central Florida in Orlando, Florida. His primary fields of research include developing low-cost methods of delivering pharmaceuticals to patients in need and even vaccines to combat terrorist bioweapons. Involvement with plant-based cures probably helped lead him to this discovery, which the college describes as a possible “breakthrough of a lifetime.” Daniell’s goal is to “relegate gasoline to a secondary fuel,” with a process that uses “plant-derived enzyme cocktails” to break down …