A Self-Sustained Wireless Multi-Sensor Platform Integrated with Printable Organic Sensors for Indoor Environmental Monitoring.

A self-sustained multi-sensor platform for indoor environmental monitoring is proposed in this paper. To reduce the cost and power consumption of the sensing platform, in the developed platform, organic materials of PEDOT:PSS and PEDOT:PSS/EB-PANI are used as the sensing films for humidity and CO2 detection, respectively. Different from traditional gas sensors, these organic sensing films can operate at room temperature without heating processes or infrared transceivers so that the power consumption of the developed humidity and the CO2 sensors can be as low as 10 µW and 5 µW, respectively. To cooperate with these low-power sensors, a Complementary Metal-Oxide-Semiconductor (CMOS) system-on-chip (SoC) is designed to amplify and to read out multiple sensor signals with low power consumption. The developed SoC includes an analog-front-end interface circuit (AFE), an analog-to-digital convertor (ADC), a digital controller and a power management unit (PMU). Scheduled by the digital controller, the sensing circuits are power gated with a small duty-cycle to reduce the average power consumption to 3.2 µW. The designed PMU converts the power scavenged from a dye sensitized solar cell (DSSC) module into required supply voltages for SoC circuits operation under typical indoor illuminance conditions. To our knowledge, this is the first multiple environmental parameters (Temperature/CO2/Humidity) sensing platform that demonstrates a true self-powering functionality for long-term operations.

A wireless bio-MEMS sensor for C-reactive protein detection based on nanomechanics.

A quick wireless label-free detection of disease-related C-reactive proteins (CRPs) using a 200-microm-long microelectromechanical systems (MEMS) microcantilever housed in a 7 x 7 mm(2) reaction chamber with a safe reusable feature is reported. The assay time ranges from about 30 min to 3 h, depending on accuracy. The deflection of the microcantilever due to specific CRP-antiCRP binding is detected using a position-sensitive detector. The converted bio-signal is transmitted by a custom designed wireless amplitude-shift-keying (ASK) transceiver IC fabricated in a 0.18 microm CMOS process. CRP concentrations from 1 microg/mL to 500 microg/mL can be detected. A 0.2-Hz 1-V ac signal instead of traditional bases/acids is applied to the bio-MEMS sensor to unbind the CRP from the microcantilever for reusability.