Battery-Free Wireless Sensors for Internet-of-Things and Cyberphysical Systems

Zero-power ubiquitous wireless sensors have been the subject of intense research in the past few years because of their wide uses in internet-of-things (IoTs), industrial 4.0, smart cities, wireless healthcare and environmental monitoring. Compared to the conventional wired connection systems, wireless platforms have the advantages of reduced area occupation, more mobilities of devices and longer interrogating distance, which enable a virtually ubiquitous access to information in a communication network. However, the development of these ever-increasing wireless nodes and the combination of heterogeneous networks have already generated a space-crowded and rich-scattering environment, which require future wireless systems with the capability to effectively suppress the electromagnetic interference and efficiently optimize the usage of space, power, and communication bandwidth. This work will theoretically and experimentally study innovative RF solutions to address the aforementioned challenges, including but not limited to (i) Compact and hybrid-fed antennas for harmonic wireless sensing applications; (ii) Absolute wireless sensing approach based on harmonic analysis enabled by frequency-hopping spread spectrum; (iii) Flexible harmonic sensors with multiplexed sensing capabilities for rapid, contactless microfluidic diagnosis

Effect of <i>Streptomyces</i> sp. HJC-D1 culture broth on MDA content and SOD, POD and CAT activities.

<p>(a) MDA contents; (b) SOD activities; (c) POD activities; (d) CAT activities. * represents a statistically significant difference of <i>p</i><0.05 when compared to the control, ** represents a statistically significant difference of <i>p</i><0.01.</p

Cell viability for <i>M. aeruginosa</i> FACHB-905 with and without exposure to <i>Streptomyces</i> sp. HJC-D1 culture broth.

<p>Cell viability for <i>M. aeruginosa</i> FACHB-905 with and without exposure to <i>Streptomyces</i> sp. HJC-D1 culture broth.</p

Biological degradation process of <i>M. aeruginosa</i> FACHB-905 by <i>Streptomyces</i> sp. HJC-D1: (a) normal cell; (b) cell walls becoming detached; (c) release of cellular contents; (d) broken cell.

<p>CW, cell wall; CM, cell membrane; PB, polyphosphates bodies; CG, cyanophycin granules; RIB, ribosomes.</p

Real-Time Monitoring of Emissions from Monoethanolamine-Based Industrial Scale Carbon Capture Facilities

We demonstrate the capabilities and properties of using Proton Transfer Reaction time-of-flight mass spectrometry (PTR-ToF-MS) to real-time monitor gaseous emissions from industrial scale amine-based carbon capture processes. The benchmark monoethanolamine (MEA) was used as an example of amines needing to be monitored from carbon capture facilities, and to describe how the measurements may be influenced by potentially interfering species in CO₂ absorber stack discharges. On the basis of known or expected emission compositions, we investigated the PTR-ToF-MS MEA response as a function of sample flow humidity, ammonia, and CO₂ abundances, and show that all can exhibit interferences, thus making accurate amine measurements difficult. This warrants a proper sample pretreatment, and we show an example using a dilution with bottled zero air of 1:20 to 1:10 to monitor stack gas concentrations at the CO₂ Technology Center Mongstad (TCM), Norway. Observed emissions included many expected chemical species, dominantly ammonia and acetaldehyde, but also two new species previously not reported but emitted in significant quantities. With respect to concerns regarding amine emissions, we show that accurate amine quantifications in the presence of water vapor, ammonia, and CO₂ become feasible after proper sample dilution, thus making PTR-ToF-MS a viable technique to monitor future carbon capture facility emissions, without conventional laborious sample pretreatment

Molecular Engineering Mechanically Programmable Hydrogels with Orthogonal Functionalization

A unique orthogonally tunable synthetic polymer hydrogel with programmable elasticity is described herein. The temporal modulation of mechanical properties was achieved by an orthogonal sulfonium-containing synthon, acting both as crosslinkable motifs and as functionalizable handles for chemical modification of the gel. The kinetic formation of <i>in-situ</i> covalent cross-linked hydrogels with ionic features enabled time-dependent mechanical behavior over weeks, a critical parameter of biomimetic substrates for cell development. The elasticity of the dynamic hydrogel was approximately 2 orders of magnitude greater than that of the ionically cross-linked sample with constant stiffness. In addition, we achieved on-demand control of the elastic properties of the hydrogels by application of a thermal stimulus of 37 °C, which provides new avenues to regulate cell behavior and fate. Furthermore, sulfonium groups and styrenyl moieties within the network provided covalent attachment sites for molecules of interest via highly efficient nucleophilic substitution and thiol–ene chemistry. This robust and orthogonal strategy has been demonstrated for temporal control of elasticity and molecular functionalization of the hydrogels as potential substrates for cell development

Molecular Characterization of Ongoing Enzymatic Reactions in Raw Garlic Cloves Using Extractive Electrospray Ionization Mass Spectrometry

Characterization of enzymatic reactions occurring in untreated biological samples is of increasing interest. Herein, the chemical conversion of alliin to allicin, catalyzed by allinase, in raw garlic cloves has been followed in vivo by internal extractive electrospray ionization mass spectrometry (iEESI-MS). Both precursors and products of the enzymatic reaction were instantaneously extracted by infused solution running throughout the tissue and directly electrospray ionized on the edge of the bulk sample for online MS analysis. Compared to the room-temperature (+25 °C) scenario, the alliin conversion in garlic cloves decreased by (7.2 ± 1.4) times upon heating to +80 °C and by (5.9 ± 0.8) times upon cooling to −16 °C. Exposure of garlic to gentle ultrasound irradiation for 3 h accelerated the reaction by (1.2 ± 0.1) times. A 10 s microwave irradiation promoted alliin conversion by (1.6 ± 0.4) times, but longer exposure to microwave irradiation (90 s) slowed the reaction by (28.5 ± 7.5) times compared to the reference analysis. This method has been further employed to monitor the germination process of garlic. These data revealed that over a 2 day garlic sprouting, the allicin/alliin ratio increased by (2.2 ± 0.5) times, and the averaged degree of polymerization for the detected oligosaccharides/polysaccharides decreased from 11.6 to 9.4. Overall, these findings suggest the potential use of iEESI-MS for in vivo studies of enzymatic reactions in native biological matrices

Mechanically Tough and Chemically Stable Anion Exchange Membranes from Rigid-Flexible Semi-Interpenetrating Networks

A series of tough and chemically stable semi-interpenetrating network anion exchange membranes (SIPN AEMs) composed of a rigid and ion-conductive component, quaternized poly­(2,6-dimethyl phenylene oxide) (QAPPO), and a hydrophilic, cross-linked, flexible poly­(ethylene glycol)-<i>co</i>-poly­(allyl glycidyl ether) (<i>x</i>PEG–PAGE) component were synthesized. The SIPN AEMs containing both rigid and flexible polymer constituents exhibited outstanding mechanical strength and flexibility and were much tougher than conventional QAPPO membranes. The introduction of the hydrophilic network ensured SIPN AEMs with high hydration numbers, which contributed to the high ion conductivity of these materials. The physical properties of the SIPN AEMs could be varied by the mass fractions of the QAPPO and <i>x</i>PEG–PAGE components, and a trade-off was observed between the samples’ conductive and swelling properties. Among the compositions studied, SIPN-60-2 (Mass_QAPPO‑60/Mass_PEG–PAGE = 2:1) with an IEC of 1.43 mmol/g was found to have balanced ionic conductivity (67.7 mS/cm at 80 °C) and swelling ratio (26% at 80 °C). The alkaline stabilities of the SIPN AEMs were evaluated in 1 M NaOH at 80 °C for 30 days. Good mechanical (72% and 74% retention in tensile strength and elongation at break, respectively) and dimensional (11% increase in water uptake) stability was retained by the SIPN AEM due to the presence of the alkali-resistant <i>x</i>PEG–PAGE network. The quaternary ammonium groups in SIPN-60-2 were found to be relatively stable (24% and 26% decrease in IEC and OH^– conductivity in 1 M NaOH at 80 °C for 30 days, respectively), and the low initial IEC and the high dimensional stability of the membrane protected the cation from severe degradation during the extended aging test

Bacterial strains and plasmids used in this study.

<p>Bacterial strains and plasmids used in this study.</p