Flexible bathroom scale

Here's another old idea that just came to mind. I was once thinking about TRIZ and the innovation trend where things go from rigid to flexible, and I applied it to bathroom scales. Current bathroom scales are firm and rigid so that the weight of an individual is fully transmitted to the measuring element (commonly some sort of spring mechanism). Unfortunately this also makes them bulky and difficult to stow away when not it use.


My idea for a flexible bathroom scale would basically turn a silicone mat into a bathroom scale. Within the mat, metal capacitor plates are embedded such that the plates are stacked vertically, and connected to a small capacitance meter. The idea is that as a user squishes the elastomer mat down, the distance between capacitor plates changes and thus the capacitance changes. This wouldn't be ueful if the measurement was taken at just one point, so of course, a matrix of these capacitors will populate the mat, and luckily we have convenient electrical engineering equations which tell us how capacitors in parallel should behave. Sum all the capacitance changes up, and the weight should then be easy to calculate.