Re: Electrostatic actuators to move robots legs...

On 9/14/24 20:21, john larkin wrote:

On Sat, 14 Sep 2024 05:55:41 GMT, Jan Panteltje <alien@comet.invalid>
wrote:
 

On a sunny day (Fri, 13 Sep 2024 20:40:55 +0200) it happened Jeroen Belleman
<jeroen@nospam.please> wrote in <vc20pt$10e68$1@dont-email.me>:
>

On 9/13/24 13:38, Jan Panteltje wrote:

On a sunny day (Fri, 13 Sep 2024 20:55:09 +1000) it happened Chris Jones
<lugnut808@spam.yahoo.com> wrote in <jSUEO.167440$QvZa.5887@fx08.ams4>:
>

On 13/09/2024 2:49 pm, Jan Panteltje wrote:

On a sunny day (Thu, 12 Sep 2024 14:43:02 +0200) it happened Jeroen Belleman
<jeroen@nospam.please> wrote in <vbuneq$8hap$1@dont-email.me>:
>

On 9/12/24 12:34, Jeff Layman wrote:

On 12/09/2024 10:45, Cursitor Doom wrote:

On Thu, 12 Sep 2024 05:00:38 GMT, Jan Panteltje wrote:
>

Artificial muscles propel a robotic leg to walk and jump:
     https://www.sciencedaily.com/releases/2024/09/240909113111.htm
>
quote:
     "
     The actuators are oil-filled plastic bags, similar to those used to
     make ice cubes.
     About half of each bag is coated on either side with a black electrode
     made of a conductive material.
     Buchner explains that "as soon as we apply a voltage to the
electrodes,
     they are attracted to each other due to static electricity.
     ...
     "
And press the fluid out....
So electrostatic actuators!

>
How does that not violate thermodynamics? You seem to be getting useful
power from zero energy.

>
How do little pieces of paper defy gravity when you put a charged comb
near them? Isn't the energy supplied by rubbing the comb against some
material to give it the charge to attract the paper? Where does the
voltage come from which is applied to the bag electrodes?
>
Didn't we discuss something like this not too long ago, or was it in
another NG?
<https://en.wikipedia.org/wiki/Electrostatic_motor>
>

>
That was right here in s.e.d in July. And no, thermodynamics, or
rather conservation of energy is not violated. It never is.
>
I don't think that they can get useful amounts of work out of these
things. The Science Daily article is useless, as always, and I did
not bother to read the paper.
>
Jeroen Belleman

>
At least they made something that works,
unlike the trillions spend at CERN that never do anything for anybody.
I would cancel all funding to CERN if they did not come up with something revolutionary and practical useful in a year.
He who does not want to see is practically blind.
>

>
Kicad and web browsers are quite useful, even if the physics is of no
interest to you.

>
html was invented long ago by somebody from CERN
   https://nl.m.wikipedia.org/wiki/Tim_Berners-Lee
quote in Dutch:
   " Timothy John (Tim) Berners-Lee (Londen, 8 juni 1955) is samen met zijn toenmalig manager, de Belg Robert Cailliau,
   de bedenker en grondlegger van de technologie en het protocol, die het world wide web of wereldwijde web, afgekort tot www,
   mogelijk maakten. Hieraan werkte hij toen hij consultant-software-engineer in dienst bij het CERN in Zwitserland was,
   van juni tot en met december 1990"
>
Timothy John (Tim) Berners-Lee  only worked at CERN from june to december 1990
So basicaly nothing to do with CERN or elementary particles etc.
There is old html server code I had somewhere from a CERN website that I once used.
Modern browsers are hopelessly bloated with other stuff, mostly for enabling more advertizing :-)
>
Without CERN he likely would have invented it anyways, maybe earlier :-)
>

>
I think Berners-Lee spent more time at CERN than that. He was a software
engineer involved in data acquisition software for physics experiments.
We were in the same department. I've been in meetings with him present.
This was in the 1980s. We were young. The subject at the time was
FastBus software libraries. FastBus was used in the LEP experiments,
but it was expensive and cumbersome and never lived up to expectations.
It died with the end of LEP.

Here is the English wikipedia site, more info, says the same thing about hiistime at CERN though
https://en.wikipedia.org/wiki/Tim_Berners-Lee
You can correct stuff on wikipedia if you want.
>

 Fastbus was an even stranger version of CAMAC.
 We used to sell CAMAC modules and crates but passed on Fastbus, went
to VME instead.
 There are still a couple of people making CAMAC, I think.  VME is
still a sizable market.
 

Good decision. Fastbus was a monster. It wasn't all that fast
either, depite being all ECL. Near the end of the 1980s, physicists
had understood that too, and they embarked on the design of another
monster: The Scalable Coherent Interconnect, or SCI. Thankfully,
that never went anywhere, as far as I can tell. I left that department
around that time and concentrated on accelerator instrumentation
instead.
Jeroen Belleman