Think Big about eVTOLs
When you think of delivery drones, you probably imagine petite quadcopters bringing pizzas,
books, or other small parcels to your front door before
humming back to Domino’s, UPS, or some other point
of origin. Well, Boeing Research & Technology
( www.boeing.com) is thinking bigger. Much bigger.
In January, the company unveiled a new
unmanned electric vertical-takeoff-and-landing (eVTOL)
cargo air vehicle (CAV) prototype that will be used in
the development of Boeing’s autonomy technology for
future aerospace vehicles. Designed and built within a
scant three months, the fully implemented version will
be able to carry a payload up to 500 lb (227 kg), or
about the weight of an average tiger, a young alligator,
or Aunt Bertha.
The prototype measures 15 ft long, 18 ft wide, and
4 ft tall ( 4. 57 x 5. 49 x 1.22 m), and weighs in at 747 lb
(339 kg). Driven by eight counter-rotating blades, it will
be able to tote the load a distance of 20 mi ( 32 km) at
speeds of better than 60 mph (97 kph).
The as-yet unnamed eVTOL is billed as a
commercial/industrial product, and the military
applications are fairly obvious. So, don’t expect to see
one land in your yard (unless, of course, you have a pet
tiger on order). ▲
Magnetic Liquid Windows
Heating, cooling, and lighting of buildings isn’t the sexiest technology topic, but what it lacks in
titillation it makes up for in real world consequences.
European surveys have revealed that these
categories account for about 40 percent of all energy
consumption in the EU, and this is closely mirrored in
the USA. For years, governments have funded
research aimed at climate protection and the
reduction of carbon dioxide emissions, and one € 5. 9
million investment has produced a novel approach to
smart windows that provide controlled shading and
solar thermal energy harvesting.
As explained in a recent article in Advanced
Sustainable Systems, a research group at the Friedrich
Schiller University Jena, Germany ( www.uni-jena.de)
has come up with a way to use magnetic liquids to
improve the energy efficiency of buildings. At the
heart of the concept is a liquid loaded with nanoscale iron
As this liquid is circulated through windows and
façades, an electromagnet controls the number of iron
particles it contains, thus allowing it to take on various
shades of gray, or even black. By adjusting the incidence of
light, it’s possible to harvest solar heat within a separate tank
and put it to use in other areas of the building.
Another nice feature is that the windows do not require
any sort of electrical connection, and they can be integrated
with existing window manufacturing technologies in double
or triple glazings.
According to the paper, “In the fully shaded state, a
typical harvesting efficiency of 45 percent of the incoming
solar power is obtained. For an average solar irradiance of
1000 W m− 2 during 800 h a−1, this corresponds to a solar
thermal harvesting capacity in the range of 360 k Wh a−1
m− 2.” Prototypes have been built on a scale of ≈200 m2
( 2,150 ft2), demonstrating their applicability to large-scale
■ Boeing’s big drone will carry up to 500 lb.
■ BY JEFF ECKERT TECHKNOWLEDGEY 2018
6 March 2018
■ A prototype smart window. Credit: Jan-Peter Kasper/FSU Jena.