The Gist of Science Reporter: February 2017
Chemists Develop World’s First Light-seeking Nanorobot
World’s first light-seeking synthetic Nanorobot has been
developed by Dr. Jinyao Tang and his team at the Department of Chemistry,
University of Hong Kong. These Nanorobots are comparable to a blood cell in
size, which makes them potentially useful to be injected into patients' bodies.
This will help the doctors remove tumours and enable more precise engineering of
targeted medications while performing the surgery. This study has been published
in October in the journal Nature Nanotechnology.
To make the nanostructures sense and respond to the
environment is a major difficulty in Nanorobot designing. Further, it is also
very difficult to squeeze normal electronic sensors and circuits into Nanorobots
with reasonable price, given each Nanorobot is only a few micrometre in size,
which is ~50 times smaller than the diameter of a human hair.
The Nanorobots developed by Dr. Tang and his team are
propelled by light and with this achievement, they have become the first
research team across the globe to explore the light-guided highly feasible and
effective Nanorobots. These tiny robots have the unprecedented ability to dance
or even spell a word under light control. Dr. Tang explains the motion of the
nanorobots in response to light shining on it as if they can 'see' the light and
drive towards it.
Natural green algae provided the inspirational idea to the
research team to design these Nanorobots. Some green algae in nature have
evolved with the ability of sensing light around it, even a single cell can
sense the intensity of light and perform photosynthesis by swimming towards it.
It took three years to successfully develop these tiny robots based on a novel
nanotree structure, composed of two common and cost effective semiconductor
materials - silicon and titanium oxide. Silicon and titanium oxide are shaped
into nanowire as a synthesizing process and are further arranged to form very
small nanotree heterostructure.
Melanin in Foams and Fabrics could Enhance their Strength
Melanin is the natural pigment that .gives colour to human
skin, hair and the iris of eyes and protects them from ultraviolet radiation
damage. Scientists have found that adding a small amount of this natural pigment
to polyurethanes makes it stronger than the material by itself. This study has
been described in the ACS journal Biomacromolecules.
The macromolecule, Polyurethane, is used in a huge range of
products - from durable foam sitting, stretchy textiles, bandages, roller
coasters, footwears, glossy coatings to insulation. Scientists already have
tried to add fillers which include; silica, graphene oxide and carbon nanotubes
to make polyurethanes more durable. But these efforts have often led to
enhancement of only one physical property - either tensile strength or
toughness, but not both.
Scientists have tried a new approach of adding melanin to
polyurethanes and new experiments show that polyurethane samples containing just
2% of melanin extracted from the ink sacs of cuttlefish' had improved both the
properties i.e. plain polyurethane to 51.5 MPa and 413 MJ/m3, respectively.
However, by further increasing content of melanin, a
relatively large- scale phase separation was formed and led to a decrease in
mechanical properties of polyurethane. Polyurethane could stretch itself by 770
percent before breaking, whereas the melanin-infused polyurethane stretched by
1,880 percent before rupturing.
New Technology Converts Sewage into Fuel
Sewage management has long been a matter of concern, but soon
the future fuel may be produced by turning human-waste into crude oil. A new
research led by the Pacific Northwest National Laboratory (PNNL), USA, has
presented a way of transforming the ordinary sewage into biocrude oil. What had
previously seemed very difficult is now possible with the new research.
Sewage or sewage sludge has long been considered a poor
component to produce biofuel because it's too wet. The technology, called
Hydrothermal Liquifaction (HTL), which uses high pressure and temperature
imitates the earth's geological conditions to form crude oil and removes the
need for drying required in a larger part of current thermal technologies which
historically made the conversion of wastewater to fuel too energy intensive and
costly. Rather than compressing and transforming the material over millions of
years, the same could be achieved in minutes. From that point, the biocrude can
be refined into fuel.
Using this technology, organic matter, for example, human
waste can be broken down into simpler chemical compounds. The material is
pressurized to 3,000 pounds for every square inch - about one hundred times that
of a car tyre. Pressurized sludge then goes into a reactor framework operating
at around 660 degrees Fahrenheit. The heat and pressure make the cells of the
waste material break into different fractions as biocrude and an aqueous liquid
There is plenty of carbon in municipal wastewater sludge and
interestingly, there are also fats," said Corinne Drennan, a Bioenergy
technologies researcher at PNNL. "The fats or lipids appear to facilitate the
conversion of other materials in the wastewater such as toilet paper, keep the
sludge moving through the reactor, and produce a very high quality biocrude
that, when refined, yield fuels such as gasoline, diesel and jet fuels."
Along with the useful fuel production, the technology could give local
governments noteworthy cost saving by wiping out the requirement for sewage
residuals processing, transport and disposal.
Along with the biocrude, the fluid phke-can be treated with a
catalyst to make other fuels and chemical products. A small amount of strong
material is additionally created, which contains essential nutrients. For
instance, early endeavours have shown the capacity to recover phosphorus, which
can supplant phosphorus ore utilized a part of fertilizer Production.