Stochastic resonance is a fundamental effect inherent to any dynamical system with three basic aspects: (a) a nonlinear, multistable behavior, (b) a weak coherent input modulation, and (c) a noise source either inherent to the system or being added to the system. In the current setup, a nanomechanical beam plays the role of the dynamical system, which can be driven nonlinearly to be in a bistable state with a large activation barrier. If the beam is driven from above (below) the resonance frequency in the frequency domain, it goes to the high (low) state. Once the beam is in one of the high or low states, it requires an enormous energy to jump over the potential barrier to go the other state. The addition of even a small amount of noise can give it a finite switching probability for crossing the barrier. For a moderate level of noise, the switching will acquire a degree of coherence with the underlying signal. If the noise is too large, it swamps the signal. In the intermediate range, there is a maximum in the switching probability, corresponding to a resonant behavior in the dynamics of the beam.or, stochastic resonance.
In physical sciences alone, the proposed research could achieve an unimaginable breadth of impact with the potential discovery of novel engineering solutions in the area of MEMS and NEMS. The exploratory research activity phased over one year will enable the training of a graduate student in developing skills for cutting-edge engineering solutions. In particular, the program will allow a comprehensive training on high-frequency circuit modeling and analysis with the available software package, hardware design for signal stimulation and transduction in the RF range for an effective detection method, and characterization of equivalent circuit parameters. The graduate students are trained on fabrication of Nano-Electro-Mechanical Systems (NEMS) from a number of materials, including silicon. The undergraduate student will be involved in the simulation and modeling of the nanomechanical structures for the proposed exploratory research in order for an early exposure to the field of nanoscale engineering.
