Nanyang Technological University, Singapore (NTU Singapore) recently
announced that Nano Sun,
a water technology start-up founded by a scientist from NTU,
has launched a 3D-printing facility to manufacture a new type of water
treatment membrane.
Unlike conventional
membrane-manufacturing processes that use acids to make polymers porous that
function as filters, Nano Sun 3D-prints millions of nanofibers layered on top
of each other, compressed into a thin membrane. This results in a new membrane
that has a faster water flow rate than conventional membranes despite having a
similar pollutant rejection rate. It allows for the construction of smaller
wastewater treatment plants, lowering the costs for land, infrastructure, and labour.
The new membrane is
also more resistant to breakage and biofouling, requiring less maintenance and
brings about greater cost efficiencies.
The first customers to
use this next-gen membrane will be two of the largest semiconductor
multinational companies in Singapore and a new municipal wastewater treatment
plant in China, which can treat up to 20 million litres of water per day – the equivalent of eight Olympic-sized
swimming pools.
Nano Sun’s new
3D-printing manufacturing plant is the culmination of a two-decade effort by
its co-founder and NTU Associate
Professor, Darren Sun, to develop and deploy his research innovations
in the fields of materials science, water chemistry, and advanced manufacturing, supported by the Singapore Economic
Development Board.
Nano Sun’s Managing Director and co-founder, Mr Wong Ann Chai, said
that finding the right market applications and validating the membranes in a
wide range of industrial and municipal wastewater recovery and intensive
purification for re-use, is their current focus.
Mr Wong stated, “Now that our technology has been
validated, we need to able to provide the most cost-effective solution for our
next phase of growth. The international market demand for industrial wastewater
treatment is going strong since most countries do not want to pollute their
scarce surface water and underground water resources”.
With the three new
wastewater treatment contracts, Mr Wong
said Nano Sun’s annual revenue is expected to reach S$10 million this year,
making it one of NTU’s most successful spin-off companies to date.
Over the next three
years, Nano Sun will expand its manpower from a Singaporean team of 18
engineers and staff to about 80, with membrane applications to be deployed in
China, Indonesia and Philippines.
Since 2015, the NTU
spin-off company has designed, commissioned and delivered over 15 water
treatment systems and plants to various governments and companies in Singapore,
China, Philippines, and Indonesia.
Growing local
enterprise – next-generation
manufacturing
NTU Vice-President of Research, Professor Lam Khin Yong said that Nano Sun’s new facility and 3D nano-printed
membrane are successful examples of how fundamental research in the
laboratories can be transformed into products with real-world impact. He added that Nano Sun’s success demonstrates
how disruptive innovations developed in Singapore can help propel the industry
forward in the new digital economy. Professor Lam added that the university
encourages and supports its faculty in innovation and commercialisation of technologies that they developed.
3d-printed water
filtration membranes
At the launch, Nano
Sun demonstrated the printing of the industry-standard PVDF (Polyvinylidene
fluoride) polymer used in conventional water filtration membranes, which is
approved by the United States Food and Drug Administration.
Using a proprietary 3D
printer, Nano Sun can print millions of PVDF nano-fibres
per second, which is accumulated on a backing material and compressed into an
ultra-thin sheet of membrane.
This gives the
membrane a much bigger surface area to trap or repel pollutants while allowing
water molecules to pass through at a faster flow rate. By adjusting how thick
or thin these unwoven fibres are layered
on top of each other, the membrane can be made into microfiltration membranes
and ultrafiltration membranes.
Further studies are now underway to develop even
better anti-fouling additives which can be combined with other materials during
the 3D-printing process.