Wireless body sensor nodes (WBSNs) are miniaturized devices that are able to acquire, process and transmit bio-signals (such as electrocardiograms, respiration or human-body kinetics). WBSNs face major design challenges due to extremely limited power budgets and very small form factors. We demonstrate, for the first time in the literature, the use of disruptive nanotechnologies to create new nano engineered ultra-low power (ULP) WBSN architectures. Compared to state-of-the-art multi-core WBSN designs, our new architectures dramatically reduce power consumption by 5.42x and footprint by 5x, while fulfilling realtime processing requirements of bio-signal monitoring applications. Our WBSN architectures achieve these results by utilizing emerging non-volatile memory technologies (such as resistive RAM and spin-transfer torque RAM) and their ultradense and fine-grained three-dimensional integration with logic (such as monolithic three-dimensional integration naturally enabled by carbon nanotube field-effect transistors).