Nonlinearity belongs to a shaded area of M/NEMS design; it is omnipresent but poorly understood. Consequently, many M/NEMS designers are very conservative about it and tend to favor designs which avoid nonlinearity rather than take advantage of it. This special session is dedicated to the development of nonlinear modeling/analysis/characterization methods and the use of nonlinearity to enhance the performance of M/NEMS devices. It is our hope that this session will see some fruitful exchanges between members from different domains (from applied mathematicians to circuit/mechanical designers) and help bridge the gap between them.