Velostat, also known as Linqstat, is a packaging material made of a polymeric foil (polyolefins) impregnated with carbon black to make it somewhat electrically conductive. It is used for the protection of items or devices that are susceptible to damage from electrostatic discharge.[1] It was developed by Custom Materials, now part of 3M.[2] Velostat is a U.S. registered trademark (4,964,564) of Desco Industries Inc. Desco Industries purchased the assets of the 3M Static Control business on January 2, 2015.[3]

Velostat is piezoresistive; its resistance changes with flexing or pressure. For instance, 25 mm2 of 0.2 mm fresh Velostat sandwiched between two electrodes has a resistance around 9 kΩ without any force applied, but only 1 kΩ when 3 Newtons of force is applied. For material that has been used, those resistances are roughly halved.[4]

Velostat's low cost and piezoresistive properties have made it popular for making inexpensive flex or pressure sensors for microcontrollers. One example is shoes which light up when the wearer steps. Since Velostat's resistance is reduced when pressure is applied, a voltage divider measuring that resistance can indicate when weight is applied or removed from the shoes.[5]

See also

References

  1. ^ Drake, N. (1996). Polymeric Materials for Electrostatic Applications. Rapra Technology. p. 131. ISBN 978-1-85957-076-0.
  2. ^ Mims, Forrest M. (2000). Mims Circuit Scrapbook. Newnes. p. 69. ISBN 978-1-878707-49-9.
  3. ^ "3M Completes Sale of Static Control Business to Desco Industries Inc". 3M News | United States. Archived from the original on 2018-07-02. Retrieved 2018-05-15.
  4. ^ Dzedzickis, Andrius; Sutinys, Ernestas; Bucinskas, Vytautas; Samukaite-Bubniene, Urte; Jakstys, Baltramiejus; Ramanavicius, Arunas; Morkvenaite-Vilkonciene, Inga (2020). "Polyethylene-Carbon Composite (Velostat®) Based Tactile Sensor". Polymers. 12 (12): 2905. doi:10.3390/polym12122905. ISSN 2073-4360. PMC 7761878. PMID 33287414.
  5. ^ "Pressure-Sensitive Conductive Sheet (Velostat/Linqstat)". adafruit.com. Retrieved 12 February 2015.