INNOVASIE | INNOVATION
STRONGEST
biomaterial ever
The strongest biomaterial ever has been assembled recently by Swedish, American and
German researchers. It consists of cellulose, properly speaking of carefully parallel orien
ted cellulose nanofibrils (CNFs). The material is stronger than steel, even stronger than
spider silk, regarded as the strongest biomaterial until recently.
By Martin van Zyl
Senwes Group Executive: Innovation
and Integrated Solutions
VAN DER WAALS FORCES
The material the research team developed
is both strong and lightweight, which
would allow it to substitute metals and
plastics in products like aeroplanes, cars
and furniture and because it is biocom-
patible, biomedical applications may also
be in the offing. The material consists
principally of cellulose nanofibrils of just 2
to 5 nanometres thickness and about 700
nanometres in length (a nanometre is a
millionth of a millimetre).
The nanofibrils suspended in water are
force-pressed through a channel just 1
mm wide, and oriented parallel through
a smart supply of pure and slightly acid
water. The fibres, compressed in this way,
adhere to each other by Van der Waals
forces, that apply to particles at the nano
scale.
The Van der Waals force, named after
Dutch scientist Johannes Diderik van der
Waals, is a general term used to define
20
the attraction of intermolecular forces
between molecules.
The researchers have succeeded in
producing threads up to 15 micrometre
thick, and several metres in length, says
researcher Stephan Roth. The researchers
could monitor the process in the X-ray
equipment of the German institute DESY,
where they could observe precisely how
the threads formed.
A lot of development work needs to
be done before the still unnamed material
can come to the market, but if industrial
production would succeed, many appli-
cations may lie ahead. The material has a
stiffness eight times that of spider silk, and
a tensile strength several times higher. It
can be woven and then be processed to
materials with unique properties, materials
stronger than glass fibre composites or
steel cables.
The researchers estimate that produc-
tion costs will be comparable to those of
other synthetic strong materials. Moreover,
this strongest biomaterial will still be biode-
gradable, being made just of cellulose. ‘We
can now transform the super performance
SENWES SCENARIO | SOMER • SUMMER 2019
from the nanoscale to the macroscale,’
says researcher Söderberg.
It opens the way for developing nano
fibre materials that can be used for larger
structures while retaining the nano fibres’
tensile strength and ability to withstand
mechanical load.
STRONGEST BIOMATERIAL EVER
The quest for more eco-friendly and ener-
gy-efficient technologies accentuates the
need to develop lightweight structural
materials with exceptional mechanical
performance from renewable resources,
Nature has developed building blocks
with excellent properties.
Lately, scientists have been seeking
ideas of mimicking natural materials’
architecture based on engineering design
principles, typically called bio-inspired
assembly. An overarching challenge in
structural material fabrication is to trans-
late the extraordinary mechanical pro
perties of nanoscale building blocks to the
macroscale bulk materials.
Abbreviated from: https://www.biobased-
press.eu/2018/05/strongest-biomaterial-ever/