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36 E L EC TR I C AL CONNEC T I ON
W I N T E R 20 1 6
SOLAR CLAMS UP
T
he electrical industry has learnt a
lot from nature; HVAC designs are
based on termite mounds, wind
turbines have been designed to replicate
the bumps on whale fins to reduce
drag and scientists have increased light
emitting diode (LED) brightness by 55%
by studying firefly scales.
When it comes to converting sunlight
to energy, there is no doubt nature is a
lot more efficient than man-made solar
panels; however, our understanding of
how nature does this is too limited to re-
engineer the process artificially.
Researchers from the University of
California decided to study giant clams in
the hope they could ‘bio-inspire’ changes
in energy creation. While LEDs are now
standard in light production today, for
a long time, clams have been producing
vibrant colours of reflected light purely
by reflecting the sun’s energy.
“We started to look at giant clams
because they are bright and attractive
visually. This led to the question: What
are the cell structures that are creating
this light, and why are they being
used?” says University of California
postdoctoral fellow and the study’s lead
author Dr Amitabh Ghoshal.
Clams are an anomaly in nature; as
filter feeders living in the nutrient-
poor waters of the Pacific and Indian
Oceans it would be expected for them
to not grow large in size due to the low
availability of nutrients.
Giant clams however grow up to
120cm long and have life spans in excess
of 100 years. This is made possible by
symbiotic photosynthetic algae living
inside the clam’s shell, which provides a
mutually beneficial relationship between
the clam and the algae.
The clam takes carbohydrates
produced by photosynthesis generated
from the algae while the algae feed on
the clam’s nitrogen rich waste.
The research is giving insight into how
the iridescent cells (cells which display
luminous colours due to reflection) -
which are located on the inside edge of
the clam’s shell - redirect the light in to
the algae located inside the clam’s shell.
The iridescent cells produce vibrant
colours with multi-layered structures of
proteins that act like mirrors to reflect
various wavelengths of light.
The research team is attempting to
build a more effective reflective structure
similar to what is found in those iridescent
cells to create an efficient distributed
light-gathering system to make three-
dimensional solar cells.
This could mean less space is required
to generate the same energy compared
with the current rooftop solar panels
and large solar farms.
“Like solar cells, photosynthesis
involves converting light into energy.
As we expand our understanding of the
clam’s system for light collection, we can
take the lessons from the clam to create
solar cells that more efficiently convert
light to energy,” Amitabh says.
Algae is filled with chlorophyll which
has strong photosynthetic properties
and there has been research which used
plant-based photosynthesis in solar
panels but Amitabh says his research is
taking a different focus.
“Instead of directly trying to mimic
putting chlorophyll into solar cells we
are more looking to be inspired by
the process where clams direct light
effectively to make solar cells.”
The research team is working in
collaboration with partners to create
some proof of concepts, so they are not
at the commercialisation stage yet.
“We are hoping many companies will
use our research for future development
of solar panels and solar technology.”
RESEARCHERS ARE
INVESTIGATING THE ROLE GIANT
CLAMS COULD PLAY IN THE
DESIGN OF POTENTIALLY MORE
EFFICIENT SOLAR PANELS.
JOE
YOUNG
REPORTS.
Giant clams could provide the answer to more efficient solar panels.
RESEARCH