Abstract: Nanoscale materials such as carbon nanotubes and silicon nanowires offer the exciting prospect of enabling low cost, low power, highly sensitive detectors for a wide variety of chemical and biological materials. The potential of these materials in sensing applications has been demonstrated by researchers around the world. However, several challenges remain to transition this technology from laboratory demonstration to real-world application in portable, battery-operated sensor devices or environmentally-powered wireless sensor network nodes. We describe some of the inherent challenges and limitations of exploiting nanomaterial resistive sensors for gas detection due to noise and process variation. In the context of energy-harvesting wireless sensor networks, the opportunities and limits of circuit techniques to compensate for some sensor non-idealities are discussed.

Abstract—A fundamental problem that miniaturized systems, such as biomedical implants, face is limited space for storing energy, which translates to short operational life. Harvesting energy from the surrounding environment, which is virtually a boundless source at these scales, can overcome this restriction, if losses in the system are sufficiently low. To that end, the 2- m bi-complementary metal–oxide semiconductor switched-inductor piezoelectric harvester prototype evaluated and presented in this paper eliminates the restrictions associated with a rectifier to produce and channel 30 W from a periodic 72- W piezoelectric source into a battery directly. In doing so, the circuit also increases the system’s electrical damping force to draw more power and energy from the transducer, effectively increasing its mechanical-electrical efficiency by up to 78%. The system also harnesses up to 659 nJ from nonperiodic mechanical vibrations, which are more prevalent