Rubber soled slippers generating static electricity

Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
Sign up Log in
60 replies · 50K views
Fred Wright said:
If I had this problem I would invest in an humidifier. They are relatively inexpensive.
That is a solution but it's yet another box to find room for and to remember to fill up with water. I remember people used to have a simple form of humidifier which was a small trough of water, hung over a CH radiator. They did look a bit 'quaint' and were a modern equivalent of antimacassars in old persons' sitting rooms. But no one seems to like my wet socks idea.
 
Physics news on Phys.org
davenn said:
leather straps were extremely common on vehicles from the 1950's - 70's.
Apparently there was a link to the static buildup as being one cause of car/motion sickness

From a physics point of view the straps must have been useless. Electrostatic charge on the car cannot affect the passengers. The car is a Faraday cage, so charge would move to the outside, and inside there would be no electric field. In addition, since the 1950's-1960's car tires are made sufficiently conductive to bleed away excess charge to Earth as fast as it is generated.

(Nor would such a strap prevent passengers to accumulate charge when leaving the car by sliding in their seat, and experience a spark when touching the door.)
 
I grew up in the 60's with winter static and, yes, you can get a real jolt. As kids we used to chase each other around, which made it all the worse when you got caught. My recollection was that leather sole shoes on Sunday were the worst but nothing seemed to spare you..

Ultimately, the solution was, and, I fear, still is, a humidifier (See also #29). Humidifiers have the advantage of also addressing the other problems of the ultra dry winter air (e.g., hair, skin, sinuses, static cling), not just the shocks. It can either be added to the HVAC for the whole house or individual units for the largest rooms. It does not have to be humid, just not so dry. Just barely below the point you start to get condensation on the inside of windows, and glasses with ice, is best.

In the 80's there were "new" ultrasonic humidifiers that were great and they are so much less expensive now. Some people have concerns about refilling and also bacteria. Refilling is what it is, for room units. There are carbon sticks you can put in the water for bacteria. I never liked adding chemicals to the water. The humidifiers we tried that used heat, rather than ultrasonic, started to get mineral deposits on the heating coils right away.
 
spareine said:
inside there would be no electric field.
I always understood that it was negative ions that came into the cab and made people feel unwell. The ions could be formed outside on sharp bits of the car body. A Faraday cage would need a very high potential to beat the air flow through the car.
I'm not actually endorsing the hypothesis about static and sickness. It is not a common problem these days - motion sickness is most likely due a subjective reaction to motion and suspensions (and roads) are much improved these days. Many remedies for this work on the placebo effect. If they work then use them.
 
sophiecentaur said:
motion sickness is most likely due a subjective reaction to motion
The last I heard (many years ago), motion sickness was attributed to the conflicting inputs to the inner ear and the eyes. It was/is considered a survival adaptation because some natural poisons, when ingested, upset the inner ear semicircular canals. The result is to regurgitate whatever was recently eaten.

This explanation is somewhat supported by the 'motion sickness' cure to watch the horizon. Those land-lubbers that have been below decks on a ship in rough weather or rode in an enclosed van on a rough road can attest to effectiveness.

Cheers,
Tom
 
Tom.G said:
motion sickness was attributed to the conflicting inputs to the inner ear and the eyes
We're going a bit off topic here, I was really just challenging the use of Faraday Cage in the argument against an electrical cause of motion sickness. The idea of the vomit reflex when your head goes woozy is well known and I could well believe it.
 
I have this problem. You can see the sparks when I touch something metal. It's awful!
We have nylon carpet and I blame this as I've never had am issue with wool carpets in the past.
I have found my slippers have to have a natural rubber sole, not synthetic. This stops the shocks. However natural rubber soles are hard to fine.
I also get zaps from my car when getting out so learned to hang onto the car door until I was completely out of the car.
The supermarket is another scary place for me. Constant zaps when touching the metal shelves to get something! Can't afford to re-sole all my footwear to natural rubber!
 
Jayne said:
I have this problem. You can see the sparks when I touch something metal. It's awful!
We have nylon carpet and I blame this as I've never had am issue with wool carpets in the past.
I have found my slippers have to have a natural rubber sole, not synthetic. This stops the shocks. However natural rubber soles are hard to fine.
I also get zaps from my car when getting out so learned to hang onto the car door until I was completely out of the car.
The supermarket is another scary place for me. Constant zaps when touching the metal shelves to get something! Can't afford to re-sole all my footwear to natural rubber!
Welcome to PF. :smile:

Sounds like you could benefit by doing a web search for clothing that does not generate static charge. What kind of material do you usually wear? Also, what is the typical relative humidity where you live?
 
berkeman said:
Welcome to PF. :smile:

Sounds like you could benefit by doing a web search for clothing that does not generate static charge. What kind of material do you usually wear? Also, what is the typical relative humidity where you live?
Thanks! 😊
There are some polyesters that I won't wear at home anymore. They're just asking for trouble! So I try to wear natural fabrics without being too pedantic about it.
I'm in lower New Zealand so not a humid climate.
It's embarrassing at the supermarket, jumping and going ouch all around the shelves, I sometimes ask people to get things for me 🤣
Apparently the trolleys get charged just by being pushed around. I get shocks off them too if I touch the metal sides.
At least I'm not there all the time like I am at home though.

I've read about using a Humidifier but this concerns me, all that extra moisture in your home in winter. We actually use a dehumidifier in winter!
 
If other people wearing the same type if clothing at the supermarket are not having the same issues, perhaps there is something else going on. Have you spoken with your family physician about this? There are some tests that your doc can have done to see if what you are perceiving as static shocks are actually a symptom of something else.
 
Reply
  • Like
Likes   Reactions: Jayne
berkeman said:
If other people wearing the same type if clothing at the supermarket are not having the same issues, perhaps there is something else going on. Have you spoken with your family physician about this? There are some tests that your doc can have done to see if what you are perceiving as static shocks are actually a symptom of something else.
Speaking to the Doc is something I've never thought of! Thank you, I might just do that.
I know other people do have issues at the supermarket as I spoke to a staff member once and she knew what I was talking about.
I remember wearing old wind up watches and the time would always race ahead on me so I gave them away! 😊
 
Reply
  • Like
Likes   Reactions: berkeman
Jayne said:
Constant zaps when touching the metal shelves to get something!
I used to demonstrate the Van de Graaf Generator in school and learned that the shock from the charged sphere was virtually non-existent if I made sure to touch it with a screwdriver, held firmly in the hand. The same thing worked well with a Tesla Transformer that we made at work. People used to think I was very daring but they didn't seem to realize that the screwdriver was taking the zap!

I'm not suggesting you should walk around the supermarket holding something that looks like a Weapon but anything metallic will do which you can hold tightly with a good contact and touch the shelves with that. Perhaps a pointed object would be best but I never looked further into it.

It may be worth a try and you could soon get into the habit. Perhaps a novel piece of jewellery could do the job.
 
Reply
  • Like
Likes   Reactions: berkeman
sophiecentaur said:
I'm not suggesting you should walk around the supermarket holding something that looks like a Weapon but anything metallic will do which you can hold tightly with a good contact and touch the shelves with that. Perhaps a pointed object would be best but I never looked further into it.
The classical object is a car key or house key.
 
When one starts getting static shocks at home from static simply put a large pot of water on the boil. That's what my Mom used to do.

I was raised in a Mediterranean climate. Hot dry summers and rainy winters. So we did this in reverse to most of you.
 
Tom G. has the right of it. Disagreement between the eyes and vestibular system is a well acknowledged symptom of alkaloid poisoning. As we were initially a roots and tubers eating sort of folk in our early evolution this was a highly selected survival mechanism.
 
Reply
  • Skeptical
Likes   Reactions: davenn
Jeff5522 said:
Spareine is correct. The rubber soles are an insulator so no electrons are transferred through them. Getting up from a chair often transfers electrons directly to your body. When you are wearing rubber soles the electrons can't pass through them easily to escape (they are an insulator) , so you get a shock when you touch something metal - you have a negative charge so the electrons pass from your body to the metal.

This is incorrect and as I said earlier is proven on a daily basis
 
Jeff5522 said:
Getting up from a chair often transfers electrons directly to your body.
A mechanism that's often neglected is Electrostatic Induction and I think it is a more common way that things can become charged than simple 'charge sharing' (which is how people describe the process). Getting up from a chair, in itself, can't deposit charges easily because there is poor contact between your body (a conductor) and the chair plastic. But your body will easily become polarised, with charges attracted to the chair and charges moving to a far point in your body.

When you touch any conducting part of the car, during driving, those 'other' charges will flow to the car (in small quantities - so no shock). This leaves you with a charge imbalance and you have that when you step out of the car. Once outside the car, if you touch the door handle, the pairs of unbalanced charges flow together and you get a shock. You don't get a shock if you kick the door closed with rubber soles (mind the paintwork) but you leave with your extra charge and get a shock when you next tough an uncharged or Earthed object.

The charges back on the car seat are still there until they slowly dissipate. The Electrophorus is described in the link above and it provides an endless supply of charge from just one statically charged source. The Energy for charging is provided by the effort of separating your backside from the seat.
 
Last edited by a moderator:
I have to wear special shoes with rubber soles to prevent back pain, so I did buy shoe covers in bulk from Amazon, although have yet to try them out. Weather is heating up here, and for a few weeks I didn't have static shock but past few days, it's returned (and I don't know why because weather has been hot still), so I will try out those shoe covers because I don't want to accidentally spark a fire, plus those shocks can be painful.
 
MaryYamada said:
I have to wear special shoes with rubber soles to prevent back pain, so I did buy shoe covers in bulk from Amazon, although have yet to try them out. Weather is heating up here, and for a few weeks I didn't have static shock but past few days, it's returned (and I don't know why because weather has been hot still), so I will try out those shoe covers because I don't want to accidentally spark a fire, plus those shocks can be painful.
Forgot to mention, I have to wear those shoes both indoors and outdoors.
 
MaryYamada said:
so I will try out those shoe covers because I don't want to accidentally spark a fire
Unless your work/live in an environment with lots of natural gas concentrated in the air (and you would smell the strong odor of Mercaptan) , the risk of starting a fire or explosion with a static shock is pretty much non-existent. :wink:
 
I don't have that natural gas issue you mention, unless you factor in our gas stove, dryer and gas fireplace, but those shocks are pretty painful...so, if only for my own pain-free peace of mind and body.....
 
sophiecentaur said:
A mechanism that's often neglected is Electrostatic Induction and I think it is a more common way that things can become charged than simple 'charge sharing'

I agree it is a good exercise to compare the person to an electrophorus, and to consider the possibility of touching ground while seated, theoretically. However, I am not sure why you refrained from estimating the magnitude of your effect of touching ground while seated. See the figure. Suppose the penetration depth of the triboelectric charge is ~1 μm if the person is sitting, then the charge separation distance in C1 is ~1 μm, or less. In contrast, the separation distance in C2 is 1 cm or more. So merely ~0,01% of the charge of C1, or less, would be transferred to C2.
In practice, it is easy to verify that touching ground while seated hardly affects the excursion of the electroscope after rising from the chair, or the propensity to spark.

electrified chair.png
 
spareine said:
So merely ~0,01% of the charge of C1, or less, would be transferred to C2.
I was thinking about it differently. I assumed that the charge separation between chair and seat would be due to friction between seat and trousers. (Why do you estimate 10mm between body and seat? Clothing (compressed) would only be a mm or less.) Displaced charge on the body would travel to the car body through the wheel and controls. The charge separation process would be gradual as the driver fidgets in her seat so no shock experienced when touching the wheel. You operate the door lock before you move off the seat so no shock. You then slide out, which produces a high PD (Q=CV) and C reduces a lot due to separation. You then turn round and touch the door and that's when you get the shock.
Iirc, I have experimented with holding the door whilst actually stepping down onto the ground and that reduced / eliminated the shock.
Second thoughts - perhaps the car body charges up when moving through dry air and the driver, inside the shell, has no charge. Stepping out of the car, the uncharged driver can then touch the charged car body but that would rely on some nifty movement to avoid touching the door handle until the driver is definitely outside it.
 
sophiecentaur said:
I was thinking about it differently. I assumed that the charge separation between chair and seat would be due to friction between seat and trousers. (Why do you estimate 10mm between body and seat? Clothing (compressed) would only be a mm or less.)
Then my diagram was not clear enough. The capacitors C1 and C2 together are a stack of three electrically charged layers: (A) the lower surface of the body, including the trousers, negatively charged due to the triboelectric effect; (B) upper surface of the seat cushion, positively charged due to the triboelectric effect; (C) the chair frame that supports the cushion, connected to Earth or the car body. C1 is the capacitor AB; C2 is capacitor BC. The distance between the charges of A and B is very small. The distance between B and C is the thickness of the cushion, at least 1 cm.

sophiecentaur said:
Iirc, I have experimented with holding the door whilst actually stepping down onto the ground and that reduced / eliminated the shock.
I thought you implied in post #48 that the final spark when leaving the car could be reduced in an earlier stage by touching the frame while driving. But now I understand you are saying that the final spark can only be reduced by touching the frame while rising from the chair. I agree with that (as in post #12).
 
spareine said:
I thought you implied in post #48 that the final spark when leaving the car could be reduced in an earlier stage by touching the frame while driving. But now I understand you are saying that the final spark can only be reduced by touching the frame while rising from the chair. I agree with that (as in post #12).
Living in UK, I don't have a lot of problems with this but I do find it quite difficult to exit a car without losing contact with it at some stage. We agree that's the critical stage. There must be a way of attaching a wire before exiting but that would be a fiddly process and I know I'd forget to do it on the driest day of the year!
spareine said:
The distance between B and C is the thickness of the cushion, at least 1 cm.
Right - I get your model now. However, I would suggest that the charge separation would occur whilst sliding / exiting and the charges would be right on the surface of the seat.

But if it were as simple as our discussion suggests, wouldn't seat manufacturers use appropriate seat fabric?
 
sophiecentaur said:
Right - I get your model now. However, I would suggest that the charge separation would occur whilst sliding / exiting and the charges would be right on the surface of the seat.
Agreed

sophiecentaur said:
But if it were as simple as our discussion suggests, wouldn't seat manufacturers use appropriate seat fabric?
Maybe the manufacturers found out that antistatic seats were low on the priority list of buyers
 
I have the same problem and it hurts like hell. But I have NO carpets in my home only ceramic tiles.