XVCF-4S200 | LINQSTAT 4 mil - 200 Ω/sq Conductive Film

Given its low surface resistance, LINQSTAT XVCF films have been successfully used as a pressure sensor making them useful for applications that require more conductivity to be able to detect more subtle pressure differences.

Introduction A force sensitive resistor (FSR) is a material which changes its resistance when a force or pressure is applied. Conductive film is an example of such force resistance material. In other words, force sensitive resistor it’s a sensor that allow you to detect physical pressure, squeezing and weight. Usually, force sensitive resistors are very simple to be made and low cost, although they are not accurate. For this reason, basically when you use FSR you should only expect to get ranges of response instead of precise results. Therefore, while FSRs can detect weight, they cannot detect exactly how many pounds of weight.                                                                                                                                                                                           

Work Mechanism FSR’s are usually composed by two substrate layers. Followed by the conductive film and the plastic spacer, which includes an opening aligned with the active area. After the spacer layer there’s the conductive print on substrate. When external force is applied to the sensor, the conductive film is deformed against the substrate. Air from the spacer opening is pushed through the air vent, and the conductive film comes into contact with the conductive print on the substrate. The more of the conductive ink area get in touch with the conductive film, the lower the resistance. Therefore, the more pressure applied on the sensor, the more the layers touch the conductive film and that makes the resistance go down.

Product Selection

• We have various grades of conductive film regarding volume conductivity, VCF < MVCF < XVCF. Typically the larger the pressure sensor, the less conductive the film needs to be. You could still use the more-conductive material, but then you are paying for conductivity that you don’t necessarily require.
• The volume resistivity is thickness dependent. Where the thickness plays a role and is particularly important for pressure sensor applications. The thinner sheets are less sensitive to pressure changes than the thicker ones (because essentially by reducing the thickness, you increase the conductivity). The minimum thickness suitable for pressure sensors is 4mil, but the 6‑mil and 8‑mil thicknesses are more common for pressure sensors.