Implementation Review of the Vera Point Force Sensitive Resistor Small Circular Sensor

For the last few months I have been trying to integrate a batch of force sensitive resistors I got from Sparkfun Electronics. They are half inch circular disks that have reduced resistance the more pressure is applied to them. In specific they are Sparkfun part number SEN-09375. I wanted to share my experiences in trying to integrate these sensors into two different projects.

The first project I attempted to integrate this sensor into was inside the center of a pillow in order to detect if people were squeezing the pillow. This didn't work at all. I originally attempted to solder to the bare metal connectors on this sensor and found out that it didn't work worth a darn and some of the leads fell off. The Vera Point implementation guide specifically states to not solder to these sensors but to use quick disconnect type connectors. That was my error. These sensors have a very high minimal force threshold. They weren't the best solution for attempting to integrate into a minimal pressure situation with dynamic movement and bending.

The second time I attempted to implement these sensors was into a pair of floor pads that you could stand on. The main problem with this was how small the stems of the sensors are. When trying to use a recommended quick disconnect type connector like a screw terminal, the bulky terminal is so close to the sensing area that it obstructs interaction with the area. In my specific case, the terminals for the sensor were so close to where people were stepping, they would step on the terminals then the sensor would come disconnected from pulling out of the quick-disconnect type terminal.

After these two scenarios I am having a difficult time of thinking about a scenario where these sensors would actually work well. Their need to be connected to quick disconnect type terminals and not hard soldered is a huge disadvantage because they are flimsy and unstable as is.

I ended up ditching these sensors completely for my hair trigger applications and am currently using a combination of conductive thread and 3M Velostat in order to fabricate custom sized hair trigger pressure sensors. The processes that Plusea at Instructables explains in Conductive Thread Pressure Sensors will work well to fabricate custom soft and durable sensors. They just take a long time to make if you hand sew them.