A thousand words
Techno Talk
Mark Nelson
… is exactly equal to the value of one picture, according to educationalists, for whom a picture is
definitely worth a thousand words. But that’s not all, as you will soon discover.
T
he logic of the thousand
words notion is not hard to grasp,
although identifying the originator of this saying is more difficult.
Wikipedia traces it back to an old
Chinese proverb, often attributed to
Confucius. Whatever the source, there’s
little doubt that seeing something is
often a better way of learning than
reading dry text in a book.
Neither technique, however, compares to watching a well-made YouTube
video on your computer, and to prove
this, I invite you to view https://youtu.
be/cM7t1Mpu7s4 where you’ll see the
commendable Dave Jones explaining the
difference between linear and switchmode methods of reducing DC voltages.
He does this in a down-to-earth and engaging way that holds your attention and
makes the subject look easy. No wonder
one of his fans writes: ‘I wish I had you
as my teacher in engineering college.’
This presentation must be worth a million words, even if some of the other
stuff on YouTube is pretty wretched.
Mushroom magic
Fungi can now be used to make PCBs or
substrates for electronic components.
Protagonists call this ‘myceliotronics’
and no, it is not an early April Fool’s
joke. Not all fungi can be used, however, and so far only one variety is
suitable. Called Ganoderma lucidum,
it’s a variety that has limited distribution in Europe and parts of China, and
is now cultivated in India. It is more
widely known for its medicinal properties, used in China for 5,000 years to
treat diseases like diabetes and cancer,
as well as bacterial and skin infections.
So, what is its use in electronics?
Martin Kaltenbrunner (Department
of Soft Matter Physics at the Johannes
Kepler University in Austria) claims it as
a ‘global first’ that could result in more
sustainable electronics. He explains
that it was, ‘more or less an accidental
discovery, as so often is the case when
it comes to science.’
To protect itself from pathogens and
other fungi, this fungus forms a closed
skin on the surface of its growing medium.
8
It turns out that this skin can be removed
easily for further processing. Scientists
can even use it directly for a project; it
just needs to be dried. ‘The skin could be
used, for example, as a flexible printed
circuit board … to manufacture electronics,’ adds Kaltenbrunner. However,
at the moment, producing pulp [for substrates] is energy-intensive and not that
sustainable, even though these fungus
skins only need waste wood to grow.
Ecological and biodegradable
The material’s robust, flexible and heatresistant properties could potentially
become a natural substitute for polymers currently used in making flexible
electronic components. Kaltenbrunner
explained that all types of printed circuit boards are made from composite
materials that are generally difficult to
separate, recycle or decompose. This
biodegradable mushroom skin, however,
is now emerging as a true alternative.
Initially, the researchers are targeting
applications in the field of medical technology, where these kinds of components
mainly need to work for periods of up
to a year. The easily degradable fungal
skin is also surprisingly heat resistant,
able to withstand temperatures of up to
250°C, an important factor when building
soldered circuits. Is there any relevance
to hobby electronics? Not yet, but just as
3-D printers have become a household
object for some enthusiasts, maybe one
day we will all be able to produce plantbased PCBs in our workshops at home!
Goodbye to batteries?
For some applications, quite possibly.
According to Infineon Technologies in
Germany, using traditional keys will be
a thing of the past in many areas of life.
The company is launching onto the market a solution that can be used to open
and close locks using mobile phones –
without the need for batteries to power
the lock. The application gets the power
it needs contactlessly from the mobile
phone, using a process widely known
as ‘energy harvesting’.
Adam White, President of Power
& Sensor Systems at Infineon, says:
‘Infineon is paving the way with a new
solution for doing away with keys. By
dispensing with batteries, we are providing, for the first time, a reliable,
low-maintenance and secure way of
opening and closing smart locks.’
To activate the lock, the mobile phone
must be held directly on it. Near-field
communication (NFC) is used to check
whether the device is actually authorised to open the lock via encryption
technology. At the same time, energy is
transferred contactlessly to a capacitor
that powers opening or closing the lock.
So how does it work?
The core of the solution is a programmable
32-bit microcontroller with a built-in NFC
front-end to make it an NFC actuation
controller. This approach enables firms
to launch miniaturised smart locks onto
the market with very few elements. The
built-in true random number generator
allows data encryption and decryption
with extremely low power consumption,
enabling developers to create complete
smart actuation devices with a minimum
number of additional components.
Continues White: ‘Our battery-less technology is especially suitable for locks that
require little mechanical effort, such as
in office furniture, hospitals and fitness
studios. Other possible applications are
bicycle locks, mailboxes and parcel boxes.
The solution thus provides greater convenience and flexibility, while at the same
time cutting the cost of key management
in private and commercial properties. It
also comes into its own when batteries in
standard smart locks run out of power, or
when keys are lost, dispensing with the
need for expensive locksmith services.’
Coda
Now you know almost everything about
a thousand words, but I’ll leave you with
a couple of linked thoughts on this subject. A thousand words are what I am
asked to deliver each month for Techno
Talk, which I have now been doing for
20 years. It is also the number of words
I need to write for my final contribution next month. But more of that in a
month’s time.
Practical Electronics | February | 2023
