From nano to bio
Techno Talk
Mark Nelson
Tiny nanogenerators embedded in skin-worn patches and activated by body movement alone can
generate electrical fields to accelerate the healing of wounds. And while plant-based foods are just
starting to replace meat and cows’ milk, it turns out that plant-based plastics have been supplanting
their petrochemical-based equivalents for several decades. It’s all go in electronics!
T
he only thing nastier than
a body wound has to be a slowhealing or totally stalled wound. I
know this from personal experience. But
what I didn’t know until I researched
this article is that electrical fields can
speed the process of cell and tissue
growth and repair when ‘kick-started’ by
gentle electrical stimulation. Although
the technique has been known for decades, the apparatus used was bulky and
expensive. However, this has spurred a
huge global research effort to reduce size
and cost – for example, the British-made
Accel-Heal Solo device (www.accelheal.
com/accel-heal-solo/). Ingenious as
this device is, it suffers from the use
of body-worn batteries that need to be
changed every two days. Therefore,
the race is on to develop small, wearable and inexpensive skin patches that
aren’t encumbered by external electrical equipment.
Nanogenerators
Someone who hopes to find the perfect
solution is bioengineer Zong-Hong Lin
of the National Tsing Hua University in
Taiwan. His research team is working to
perfect tiny electric generators to bring
wearable, electric, wound-healing devices to clinical practice, avoiding the
need for batteries. Some nanogenerators employ synthetic materials such as
quartz analogues, ceramics and polymers
to generate an electric current when exposed to mechanical stress.
Another device, called a ‘triboelectric
nanogenerator’ (TENG), produces an
electric potential when two interfacing
materials come in and out of contact with
each other (eg, rubbed). Scientists have
experimented with TENGs that generate
electricity from breathing movements, for
example, to accelerate wound healing in
rats. They have also loaded TENG patches
with antibiotics to facilitate wound healing by also treating localised infection.
‘Piezoelectric and triboelectric nanogenerators are excellent candidates for
self-assisted wound healing due to their
light weight, flexibility, elasticity and biocompatibility,’ declares Lin. ‘But there
are still several bottlenecks.’
8
For example, they still need to be
customised since wound dimensions
vary widely. They also need to be firmly attached without being degraded or
corroded by the wound environment.
‘Our future aim is to develop costeffective and highly efficient wound
dressing systems for practical clinical
applications,’ concludes Lin.
Two different products sharing
exactly the same sales pitch
Sounds confusing? Well, yes, and dodgy
too. It involves a highly suspect remedy
for sluggish broadband, and if you like
having your intelligence insulted with
crazy techno-nonsense, you’ll love this.
Take a look at https://getwifiblast.com/
blog/wifi-livuk.php and then read http://
wifi-upgrade.com. How a Wi-Fi extender can cure bandwidth throttling I just
cannot figure. The ‘eminent university
professor of computer science’, Richard
Stalworth PhD, who gives the erudite explanation about ‘keeping the hose open’
all the time to give you internet at full
speed is untraceable to any university.
But leaving that aside, does the product
work? Sadly not. According to Trustpilot,
92% of customers think it’s utter rubbish (https://uk.trustpilot.com/review/
wifiblast.com). Customers complain
about receiving products with two-prongs
that do not plug into their mains outlet
and a refusal to give any refund. One irate
buyer writes: ‘The internet speed is slower with the Wi-Fi extender than without
and it does nothing to improve the dead
spots in the house. I believe there is more
than one specification of the extender.
What they advertise is the 1,200Mbps
specification, but what I received is the
300Mbps specification. Considering my
broadband has 1,000Mbps download
speeds (tested!), the 300Mbps specification just doesn’t cut it.’
Just Google the two words ‘Wifiblast’
and ‘Scam’ together; you will take less
than 60 seconds to reach a conclusion!
Plant based
Finally, a follow-up to last month’s tales
of eco and ethical electronics. It’s about
bioplastics for electronics and provides
an interesting slant on where things are
headed. This is because it’s not just active and passive components that go into
electronic products; most merchandise
also involves a chassis, an enclosure and
much more. These ancillaries often involve the use of plastics and most plastics
are derived from increasingly expensive
petrochemicals.
But pause for a moment; are there
alternative plastic materials? Yes, you
can use bioplastics made sustainably
from 50% to 100% renewable plantbased ingredients such as corn starch,
sugar and vegetable oils, alongside cellulose from waste offcuts of cotton or
wood. Using renewable raw materials
helps conserve the world’s limited (and
geographically restricted) supply of
petroleum and reduces CO2 emissions
on average when compared to conventional petroleum-based raw materials.
Bioplastics are a good option for longlasting products, ensuring a positive
environmental impact. At the same time,
these plastics are just as sturdy, durable,
and recyclable as conventional plastics.
Even better, bioplastic mouldings that
have reached the end of their lifecycle
can be ‘re-granulated’ into plastic material that does not have to be made afresh,
further conserving resources and energy.
Is it all good news?
Almost, says K&M, a firm that has been
using bioplastics in equipment for the
broadcast, music and home studio industries for several decades. Its bio-based
plastics are just as sturdy and durable
as petrochemical-based materials. The
shift to bio-based plastics does, however, require extensive (and expensive)
development work, and not all bio-based
plastics have the properties required for
some products. Also, not all bio-based
plastics are automatically biodegradable.
Long-lasting products that are expected to remain in use under all climatic
conditions for years cannot be made
biodegradable or compostable using current technologies. Overall, however, the
range of products that can be made from
bioplastics is growing constantly, as is
the industrial adoption of this material.
Practical Electronics | May | 2022
