Ionogels are ideal candidate materials for flexible sensors, but their stretchability and fatigue resistance are limited. Herein, highly stretchable, fatigue-resistant, electrically conductive, and temperature-tolerant ionogels are investigated and further applied in fabricating high-performance flexible sensors. The ionogels consist of a poly­(acrylic acid) (PAA) network and a commonly used room-temperature ionic liquid (RTIL) named 1-ethyl-3-methylimidazolium dicyanamide ([EMIm]­[DCA]). Dually acrylated Pluronic F127 (F127DA) was utilized to cross-link the PAA network, and [EMIm]­[DCA] was physically confined in the PAA network. Because of their special cross-linking structure, the PAA ionogels are highly stretchable (>850%), tough, and fatigue-resistant, and they are also conductive, transparent, and temperature-tolerant because of the existence of [EMIm]­[DCA]. On the basis of their integrated performances, the PAA ionogels were further utilized to fabricate strain sensors and pressure sensors. The ionogel-based strain sensors have high sensitivity, low response time (200 ms), wide strain-sensing range (0–750%), excellent durability (>1400 cycles), and good temperature tolerance and can be applied to detect various human motions. The pressure sensors also have a high response speed (256 ms) and excellent sensitivity (GF = 0.73 kPa–1), which offers an opportunity to detect force generated by finger touching and water droplets.

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Protecting groundwater from nitrogen contamination is an important public-health concern and a major national environmental issue in China. In this study, we monitored water quality in 29 wells from 2009 to 2010 in a village in Shanghai city, whick belong to typical rural-urban continuum in China. The total N and NO3-N exhibited seasonal changes, and there were large fluctuations in NH4-N in residential areas, but without significant seasonal patterns. NO2-N in the water was not stable, but was present at high levels. Total N and NO3-N were significantly lower in residential areas than in agricultural areas. The groundwater quality in most wells belonged to Class III and IV in the Chinese water standard, which defines water that is unsuitable for human consumption. Our health risk assessments showed that NO3-N posed the greatest carcinogenic risk, with risk values ranging from 19×10−6 to 80×10−6, which accounted for more than 90% of the total risk in the study area.

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