Sensors Expo & Conference 2019

Hoffmann + Krippner, Inc 

An introduction to the line of Sensofoil® membrane potentiometers.

What is Sensofoil®?

In our last blog post, we answered the question, “What is a membrane potentiometer?” Today, we’re going to talk about Sensofoil®, the Hoffmann + Krippner brand of membrane potentiometers, and how it differs from others.

The name gives you the first clue of how Sensofoil® membrane potentiometers stand out. In addition to using them as normal potentiometers (i.e., as set-point generators in input devices like hand-held controls), they can also be used flexibly as highly accurate and reliable linear and rotary position sensors. The ultra-thin design means they fit seamlessly into restricted installation conditions.

Sensofoil® refers to a family of membrane potentiometers. The flagship PET-PET model uses conductive ink printed onto flexible PET foils (hence the “foil” part of the name), including a resistive track on the bottom foil and a top foil that works as a tap. This construction offers an excellent life span. This foil-on-foil design can also be fully enclosed with an IP rating up to IP65.

In addition, the Sensofoil® family also includes alternative designs to work within a wide variety of applications and conditions.

For example, one version can be printed directly onto FR4, if the customer has an application where they’d attach the membrane potentiometer to the enclosure with screws rather than an adhesive backing. For applications at particularly high temperatures – as in automotive, aerospace, and industrial settings – the Sensofoil® family also includes a PET-Hybrid formulation that can operate at more extreme temperatures of up to +85°C. Altogether, the Sensofoil® family includes the following lines:

Sensofoil® PET-PET A durable, ultra-thin design that works within a wide temperature range
Sensofoil® PET Hybrid Particularly resistant design that works with high temperatures
Sensofoil® PET Magnet Contactless design with an especially long-life span
Sensofoil® FR4-PET Flat design with various connection options
Sensofoil® FR4 Hybrid Particularly resistant design that works at the greatest temperature range
Sensofoil® FR4 Magnet Contactless design that works especially well with electronic equipment

Operation is identical with all forms of the Sensofoil® membrane potentiometer. With a finger or wiper, pressure is applied to the collector membrane, causing contact between the metal strip and base membrane. The resultant voltage is proportional to the distance, angle, or position being measured.

Sensofoil® potentiometers can be easily customized to required length, angles, and resistance values, so that they can be adapted to fit perfectly into existing applications.

For more information about, including links to datasheets, click here. For answers to specific questions, please contact us.

Please visit our case studies for various application examples.