SaM ~ Real Worlds Example • Table of Piezoresistive Coefficients Values

IMPORTANTE So here’s a table which shows you the three different piezocoefficients in the crystallographic axis for $n$-type piezoresistors or $p$-type piezoresistors, which have a doping level which gives this value of the base resistivity:

• $p_e$ is the fixed value of the doping level (or concentration of dopants)
• And you can find here values which are very different for both the two materials, both in value and in sign.
• So actually you can explore this kind of technology to have either positive sensitivity or negative sensitivity.
• So by selecting the doping type, the orientation, you can have strain gauges with opposite sensitivity.
• And this will simplify sometimes differential measurement.
• So this is a “freedom degree” for designing these kind of devices.