A multiharvesting system conception focused on low-voltage (up to 2.5 V) and low-power applications is presented and validated as a point-of-view system. Using just this application-specified integrated circuit, with a total quiescent power consumption of 160 μW, the harvesting system is able to collect and manage energy from different power sources, such as solar light (indoor environment), vibration (low-voltage piezoelectric generators), and electromagnetic induction (operating with a carrier frequency of 13.56-MHz regulated band). The maximum total power harvested with the addition of the three harvesting sources is around 6.4 mW, for the operating conditions defined by a PZT at 7 m/s ² at 80 Hz, 1500 lx for a laboratory illumination, and 200 mW emitted by a base transmitter at 25-mm distance between coils. A broad and detailed description of all low-power-consumption circuits involved in the multiharvesting system is described, emphasizing their design for low-voltage and low-power applications.

The concept and design of a power-conditioning circuit for an autonomous low-power system-in-package (SiP) is presented in this paper. The SiP's main power source is based on the use of micropiezoelectric generators. The electrical model of the power source, which has been obtained based on experimental measurements and implemented on Cadence Analog Artist's Spectre simulation environment, is explained. The model has been used to simulate the power source with the power-conditioning electronics over the entire design process. Finally, the simulated and experimental results of the developed integrated power circuits, which are formed by a rectifier and a low-power bandgap reference voltage source to define the threshold voltage for the closed-loop regulation process, are also shown. These circuits have been designed using a commercial 0.13-mum technology from ST Microelectronics through the multi-projects circuits (CMP) techniques of informatics and microelectronics for integrated systems architecture (TIMA) service.

In this paper, we introduce a cooperative medium access control (MAC) protocol, named cooperative energy harvesting (CEH)-MAC, that adapts its operation to the energy harvesting (EH) conditions in wireless body area networks (WBANs). In particular, the proposed protocol exploits the EH information in order to set an idle time that allows the relay nodes to charge their batteries and complete the cooperation phase successfully. Extensive simulations have shown that CEH-MAC significantly improves the network performance in terms of throughput, delay and energy efficiency compared to the cooperative operation of the baseline IEEE 802.15.6 standard.

Bacteria concentration and detection is time-consuming in regular microbiology procedures aimed to facilitate the detection and analysis of these cells at very low concentrations. Traditional methods are effective but often require several days to complete. This scenario results in low bioanalytical and diagnostic methodologies with associated increased costs and complexity. In recent years, the exploitation of the intrinsic electrical properties of cells has emerged as an appealing alternative approach for concentrating and detecting bacteria. The combination of dielectrophoresis (DEP) and impedance analysis (IA) in microfluidic on-chip platforms could be key to develop rapid, accurate, portable, simple-to-use and cost-effective microfluidic devices with a promising impact in medicine, public health, agricultural, food control and environmental areas. The present document reviews recent DEP and IA combined approaches and the latest relevant improvements focusing on bacteria concentration and detection, including selectivity, sensitivity, detection time, and conductivity variation enhancements. Furthermore, this review analyses future trends and challenges which need to be addressed in order to successfully commercialize these platforms resulting in an adequate social return of public-funded investments.