by smaller ones that make a wider
variety, adapting to customers’
The technology can create
lighter, stronger parts, and complex shapes that aren’t possible
with conventional metal fabrication methods. It can also provide more precise control of the
microstructure of metals. In 2017,
researchers from the;Lawrence
Livermore National Laboratory
announced they had developed
a 3-D-printing method for creating stainless-steel parts twice as
strong as traditionally made ones.
Also in 2017, 3-D-printing company Markforged, a small startup
based outside Boston, released
the first 3-D metal printer for
Another Boston-area startup,
Desktop Metal, began to ship its
first metal prototyping machines
in December 2017. It plans to begin
selling larger machines, designed
for manufacturing, that are 100
times faster than older metal printing methods.
The printing of metal parts is
also getting easier. Desktop Metal
now offers software that generates designs ready for 3-D printing.
Users tell the program the specs of
the object they want to print, and
the software produces a computer
model suitable for printing.
GE, which has long been a proponent of using 3-D printing in its
aviation products (see “ 10 Breakthrough Technologies of 2013:
Additive Manufacturing”), has a
test version of its new metal printer
that is fast enough to make large
parts. The company plans to begin
selling the printer in 2018.
Scientists have begun to forge embryos
out of stem cells.
Without using eggs or
sperm cells, researchers
have made embryo-like
structures from stem cells
alone, providing a whole new
route to creating life.
WH Y IT MATTERS
Artificial embryos will make
it easier for researchers
to study the mysterious
beginnings of a human life,
but they’re stoking new
University of Cambridge
University of Michigan
In a breakthrough that redefines how
life can be created, embryologists
working at the University of Cam-
bridge in the UK have grown realistic-
looking mouse embryos using only
stem cells. No egg. No sperm. Just
cells plucked from another embryo.
The researchers placed the cells
carefully in a three-dimensional scaffold and watched, fascinated, as they
started communicating and lining up
into the distinctive bullet shape of a
mouse embryo several days old.
“We know that stem cells are
magical in their powerful potential
of what they can do. We did not
realize they could self-organize so
beautifully or perfectly,” Magdelena
Zernicka-Goetz, who headed the
team, told an interviewer at the time.
Zernicka-Goetz says her “
synthetic” embryos probably couldn’t
have grown into mice. Nonetheless,
they’re a hint that soon we could have
mammals born without an egg at all.
That isn’t Zernicka-Goetz’s goal.
She wants to study how the cells of
an early embryo begin taking on their
specialized roles. The next step, she
says, is to make an artificial embryo
out of human stem cells, work that’s
being pursued at the University of
Michigan and Rockefeller University.
Synthetic human embryos would
be a boon to scientists, letting them
tease apart events early in development. And since such embryos
start with easily manipulated stem
cells, labs will be able to employ a
full range of tools, such as gene editing, to investigate them as they grow.
Artificial embryos, however, pose
ethical questions. What if they turn
out to be indistinguishable from
real embryos? How long can they
be grown in the lab before they feel
pain? We need to address those
questions before the science races
ahead much further, bioethicists say.