Considerations on pre-stress in a 3D-printed capacitive force/pressure sensor

In this work, we infer the influence of pre-stress in the design of a capacitive force/pressure sensor. For this purpose, experimental plans, so-called Designs of Experiments (DoEs), are employed. Based on these designs, not only the influence of design parameters can be inferred, but also a prediction model, which uses the design parameters as predictors, can be determined. Rapid prototyping technologies, such as the considered 3D- and inkjet-printing processes, provide major advantages such as flexibility in design. At the same time, such processes lead to inhomogeneous material properties. The presented methodology, consequently, aims at determining the variations in sensor read-out due to pre-stress influence. A combination of Response-Surface-Method DoEs for design variables and randomized DoE of noise variables (i.e. the varying material properties) is employed. We demonstrate the influence of pre-stress on the considered geometry as well as the setup of a suitable prediction model for the read-out.