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Speaker gives crystal clear sound new meaning
ClearView Audio, Waltham, Mass., created a new glass speaker
named Clio that boasts an “invisible” design consisting of an ultra-thin,
curved acrylic glass transducer, which outputs sound in multiple direc-
tions. Clio’s patented Edge Motion audio systems use a differentiating
mechanical principal to generate sound—instead of pushing from be-
hind, like traditional cone speakers, Edge Motion-driven speakers actu-
ate a thin membrane along the side in a manner that creates an
extremely efficient, piston-like motion in front. The speaker uses a sin-
gle piece of curved acrylic glass that sits on a dock, which vibrates it in
a finely tuned way so that it can play music. Clio uses a 2-in. woofer and
piezoelectric actuators in its base, which stimulate two thin membranes
(one per channel) running along both sides of its transparent curved
transducer, producing 360° stereo sound emitted from both the front
and rear faces of the 1-mm-thick acrylic material. .
Fire-resistant paper handles the heat
Researchers from the Shanghai Institute of Ceramics, Chinese Academy of
Sciences, developed a new paper that is resistant to fire and high temperatures
(>450°C). It is made from a calcium phosphate compound, hydroxyapatite (HAp),
Ca10(PO 4)6 (OH)2, and can potentially be used for both printing and writing. Chemi-
cally, the main component of the conventional paper is cellulose, a natural polymer ex-
tracted from the pulp of wood or grass. Other minor components, such as bleaching
agents and additives, are also part of the mix. To have the characteristics necessary for
high-performance printing, the paper must be coated with a very thin layer of inor-
ganic material.
“HAp is a calcium phosphate with high biocompatibility and essentially no tox-
icity. It is white in color, abundant in nature, nonflammable, and high-temperature
resistant. Therefore, it is an ideal candidate for fabricating paper. However, the most
challenging problem is its low flexibility. To overcome this, we adopted HAp ultra-
long nanowires as the paper-making material,” explains Professor Ying-Jie Zhu.
.
Ancient Chinese pottery contains rare form of iron oxide
New analysis of ancient Jian wares reveals the distinctive pottery con-
tains an unexpected and highly unusual form of iron oxide. This rare com-
pound, called epsilon-phase iron oxide, was only recently discovered and
characterized by scientists and so far has been extremely difficult to create
withmodern techniques. “What is amazing is that the ‘perfect synthesis con-
ditions’ for epsilon-phase iron oxide were encountered 1000 years ago by
Chinese potters,” says Catherine Dejoie, scientist at University of Berkeley
Laboratory’s Advanced Light Source, Calif.
Jian wares, such as tea bowls, are famous for their shiny black glaze
and variable brown and silvery surface patterns known as “oil spot” and
“hare’s fur.” The ceramic bowls, produced by the thousands in giant kilns,
were made during the Song dynasty in the Fujian Province of Southeast
China between 960 and 1279 AD. Analysis reveals that hare’s fur patterns
contain small quantities of epsilon-phase iron oxide mixed with hematite,
while oil spot patterns boast large quantities of highly pure epsilon-phase
iron oxide, an unexpected finding. Marked by extremely persistent mag-
netization, epsilon-phase iron oxide could hold the key to better, cheaper
permanent magnets used in data storage and other electronics.
ADVANCED MATERIALS & PROCESSES • SEPTEMBER 2014 5
interest
of material
Printing on HAp paper (top).
The material is fire resistant
(bottom). Courtesy of
Ying-Jie Zhu.
Modern replica of a Tenmoku tea bowl
(top) with “oil spot” surface patterns
produced by Prof. Weidong Li,
Shanghai Institute of Ceramics.
Close-up of the oil spot pattern from
an ancient Jian ware provided by the
Museum of Fujian Province.
Clio, a new “invisible” speaker, is available in
silver, bronze, or charcoal hues.