Nonlinearity and parametric pumping in sensors: Opportunities and limitations

The push towards ever smaller resonant sensors has led to the increased importance of nonlinear behavior and noise in their operation. These aspects of the response often set limits on sensor performance due to considerations of signal strength and quality. However, recent work has demonstrated that nonlinearity can also be used in a constructive way to improve performance in some applications, for example, by reducing noise or providing amplification through parametric pumping via mode coupling. In order to optimize sensor performance, it is important to understand the sources of nonlinearities so that their effects can be manipulated, either reduced or enhanced, by design and/or tuning. Here we provide a brief overview of these issues as they relate to micro-scale sensors and describe specific examples to demonstrate how one can account for nonlinearity in sensor design.