David Kirkpatrick

September 6, 2010

Self-assembling and reassembling solar cells

Okay, just yesterday I blogged that a lot of the time the mundane “a ha” moment that puts together well-known materials and processes leads to scientific advancement (the case I was referring to in the post was a simple acid bath technique that made creating solar cells much cheaper). And then again sometimes the big sexy breakthrough gets the headline (as usual) and really deserves it.

If this technique for solar cells that self-assembles the light-harvesting element in the cell, and then breaks it down for re-assembly essentially copying what plants do in their chloroplast, is able to reach acceptable levels of efficiency, it will be an absolute game-changer. Instead of a solar cell that’s (hopefully) constantly bombarded with the full effect of the sun and constantly degrading under the solar assault, these cells will essentially be completely renewed by each reassembly. No degradation over time, just a brand new light-harvesting element with a relatively simple chemical process.

From the second link:

The system Strano’s team produced is made up of seven different compounds, including the carbon nanotubes, the phospholipids, and the proteins that make up the reaction centers, which under the right conditions spontaneously assemble themselves into a light-harvesting structure that produces an electric current. Strano says he believes this sets a record for the complexity of a self-assembling system. When a surfactant — similar in principle to the chemicals that BP has sprayed into the Gulf of Mexico to break apart oil — is added to the mix, the seven components all come apart and form a soupy solution. Then, when the researchers removed the surfactant by pushing the solution through a membrane, the compounds spontaneously assembled once again into a perfectly formed, rejuvenated photocell.

“We’re basically imitating tricks that nature has discovered over millions of years” — in particular, “reversibility, the ability to break apart and reassemble,” Strano says. The team, which included postdoctoral researcher Moon-Ho Ham and graduate student Ardemis Boghossian, came up with the system based on a theoretical analysis, but then decided to build a prototype cell to test it out. They ran the cell through repeated cycles of assembly and disassembly over a 14-hour period, with no loss of efficiency.

March 28, 2008

Nano, solar and other KurzweilAI.net news

Different format today for the KurzweilAI.net newsletter highlights. There is so much good stuff I’m dropping bits directly from the newsletter. Today features solar, stretchy silicon, quantum computing news, self assembly, electricity producing nanotubes, and a possible successor to silicon — graphene.

Do follow the links.

From the newsletter:

More-Powerful Solar Cells
Technology Review Mar. 27, 2008
An MIT researcher has found a way
to improve the efficiency of
multicrystalline silicon solar cells
by 27 percent without raising costs,
making them as efficient as the more
expensive single-crystal cells. The
first cells incorporating the new
technology are predicted to cost
$1.65 per watt, compared to $2.10
per watt today….

Stretchy circuits promise elastic
NewScientist.com news service Mar. 27, 2008
University of Illinois at
Urbana-Champaign researchers have
made stretchable and flexible
silicon and plastic integrated
circuits that are just one
crystal–1.5 microns–thick. The
circuits are designed so that the
plastic, not the silicon, absorbs
most of the stress when the chips
are bent. Until now, integrated
circuits have been limited by…

Silicon chips for optical quantum
KurzweilAI.net Mar. 28, 2008
Bristol University researchers have
demonstrated the world’s smallest
optical controlled NOT gate–the
building block of a quantum
computer–fabricated from silica
wave-guides on a silicon chip. The
team generated pairs of photons,
each encoding a quantum bit or qubit
of information. They coupled these
photons into and out of the…

Nanomaterial turns radiation
directly into electricity
NewScientist.com news service Mar. 27, 2008
Two researchers–a former Los
Alamos National Laboratory engineer
and an Alabama A&M University
researcher–have developed highly
efficient nanotube-based tile
materials that can convert
radiation, not heat, from nuclear
materials into electricity. The
tiles are made of carbon nanotubes
packed with gold and surrounded by
lithium hydride….

Self-Assembled Materials Form Mini
Stem Cell Lab
KurzweilAI.net Mar. 28, 2008
Northwestern University researchers
have built self-assembling thin-film
sacs able to hold human stem cells
for four weeks in culture, keeping
the cells separated while allowing
proteins to cross the membrane. This
new mode of self-assembly from a mix
of peptide amphiphiles and
biopolymers also can produce thin
films whose size and shape can be…

Is Graphene the New Silicon?
KurzweilAI.net Mar. 28, 2008
University of Maryland physicists
have found that graphene conducts
electricity at room temperature with
less intrinsic resistance than any
other known material. Graphene, a
new material that combines aspects
of semiconductors and metals, is one
of the materials being considered as
a potential replacement for silicon
for future computing. The…