Working Principle of the Paper-Based Force Sensor
The sensing principle of the paper-based force sensor is
based on the piezoresistive effect of conductive materials
patterned on a paper structure (a cantilever beam in this
work). Many MEMS sensors (including commercial devices)
also take advantage of the piezoresistive effect [8], but they
are typically constructed from silicon-based semiconductor
materials. Instead, we used paper as the structural material
for construction of the devices.
Figure 1A shows a schematic diagram of a simple,
paper-based force sensing cantilever. In this device, a carbon
resistor is located at the root of the cantilever. When a force is
applied to the beam structure, the resistor will experience a
mechanical strain/stress, which then induces a change in
resistance of the resistor. Measuring the change in resistance
allows quantification of the applied force.