also: anti-static bag, ESD bag
Velostat is a piezoresistive material, meaning it’s electrical resistance decreases when pressured. When sandwiched between two conductive layers, it has a wonderful range for making pressure and bend sensors. It can also be used for resistive sensing over distance, position sensing.
Velostat is a back, opaque, volume-conductive, carbon-impregnated polyolefin. The electrical characteristics are not affected by age or humidity (but they do change when melted under the iron).
Velostat is the brand name for this material manufactured by 3M. Linqstat is the same thing, just manufactured by another company, Caplinq. This is also the material from which the black anti-static storage bags for sensitive electrical components are made. Although not all anti-static electronics bags have the same piezoresistive properties as Velostat! From experience we have found that silver and transparent bags are not pressure sensitive, and unfortunately not all black bags are either. But your chances are high, if the bag is black. Bring your multimeter to the store and maybe you can test them before you buy them.
It is also used to make helmets to protect against alien abduction.
>> http://www.stopabductions.com/
Anti-Static Plastic Bag Links
>> http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=320843661626 (UK, thanks to Tom S. for this link)
>> http://www.packagingknowledge.com/Anti_Static_Bags.asp
>> http://www.esdjournal.com/techpapr/ryne/esdbags.htm
>> http://en.wikipedia.org/wiki/Electrostatic_discharge
>> http://www.huebner-elektronik.de/ (Anti-static Lagebeutel, Erfurt, Germany)
Suppliers of velostat and Linqstat
>> http://www.lessemf.com/plastic.html (New Jersey, USA)
>> http://www.blockemf.com/catalog/product_info.php?cPath=762&products_id=5247
>> http://www3.3m.com
>> http://www.caplinq.com/blog/linqstat-volume-conductive-film-for-emf-shielding_37/ (Canada)
The film thickness we recommend for this purpose and for pressure sensors is 4mil (0.1mm). We also have 8mil (0.2mm) thickness available, but other tahn being less flimsy than the 4mil thickness, we don’t see any real advantage, and it is a more expensive material.
We currently offer the 4mil thickness by the meter, but if there is significant demand, we could consider selling the 8mil thickness also by the meter.
hi, you have to understand from the Internet sales of black conductive bags, we are a Hong Kong company has plants in Dongguan, China, specialized production and processing all kinds of conductive bags, able to reach any port terminals, hoping to have the opportunity to co-operation, thank you
Product Brief:Our conductive bags are ideal for packing explosives and sensitive electronic components. These are made of high quality raw material using latest technology. Moreover, these are tested on various parameters before being supplied to our clients. The salient features and specifications are as follow:
• Carbon impregnated polyethylene of 40-200 micron thickness.
• Surface resistance less than 10^6 ohms/sq
Hi I am finding it really difficult to find anyone who sells velostat in the UK, any pointers please?
Thanks Alison.
Hi Alison,
i don’t know of any places in the UK but try asking MUTR (www.mutr.co.uk) to consider stocking it. and i will look into it and let you know if i find anything. alternatively you can order Linqstat from Caplinq or try to get your hands on some black plastic electronics anti-static storage bags. these tend to be made from Velostat.
Feedback from Caplinq:
CAPLINQ offers a Velostat alternative called LINQSTAT and we stock it in both Canada and the Netherlands. You can see the link here: http://www.caplinq.com/linqstat-vcf-s-series-linqstat-volume-conductive-film.html We will soon be offering standard sizes in 2mil, 4mil and 8mil. Check the site for updates. Due to popular demand, within a month, we are also going to offer a silver conductive Velcro (Hook & Loop) as well and anti-static fabric. Contact us for status
[...] 9月16日に行われた第1回ワークショップの写真です。ネオプレーンと導電性のVelostat素材を使って曲げセンサーと圧力センサーをつくりました。 #gallery-1 { margin: auto; } #gallery-1 .gallery-item { float: left; margin-top: 10px; text-align: center; width: 33%; } #gallery-1 img { border: 2px solid #cfcfcf; } #gallery-1 .gallery-caption { margin-left: 0; } [...]
Hi, I tried electrostatic foam as a pressure sensor, high density 1/2 inch from Techni-Tool. It doesn’t conduct at all, let alone exhibit variable resistance with pressure. Is that impossible? Please recommend a source for foam that can perform as a variable pressure sensor. Thanks!
ASSALAM U ALEKUM !
i m doing project regarding velostae in surveillence system . plz give me any details about its working and its usage with respect to security.
i’d b very grateful 2 u all
regards
Hi,
I cant find velostat in Malaysia..anyone know the closest place i could get it from?
Thanks,
Rizwan
Hey there, there is an alternative to using Velostat or Linqstat that can be found on quite a few electronics sites across the world; the alternative can also be found on ebay! Black conductive bags work as a very good replacement for Velostat, it works just the same way and it’s cheaper than Velostat too. I got 50 10″ x 12″ black conductive bags from this link for £4.25 (might be dead by the time you click it) http://www.ebay.co.uk/itm/ws/eBayISAPI.dll?ViewItem&item=320843661626
That’s 2500x3000cm or 2.5 x 3 metres of material that you could use, whereas Velostat costs more than that for usually about 1 x 1.2 metres or something! There are similar deals on ebay sites across the globe, so don’t miss out if you can’t get your hands on Velostat or Linqstat. I’m from the UK, so ebay’s a great resource for me =)
does anybody know resistance of the Velostat (ohm.cm)?
can we use conductive foam instead of velostat?