Electrospun cellulose-based poly N-vinylpyrrole (PNVPY) and poly (3-hexylthiophene) (P3HT) nanofibrous mats and their influence on nerve cell behavior with electrical stimulation.

Iron is a trace mineral that plays a vital role in the human body. However, absorbing and accumulating excessive iron in body organs (iron overload) can damage or even destroy an organ. Even after many decades of research, progress on the development of noninvasive and low-cost tissue iron detection methods is very limited. Here we report a recent advance in a room-temperature ultrasensitive biomagnetic susceptometer for quantitative tissue iron detection. The biomagnetic susceptometer exploits recent advances in the magnetoelectric (ME) composite sensors that exhibit an ultrahigh AC magnetic sensitivity under the presence of a strong DC magnetic field. The first order gradiometer based on piezoelectric and magnetostrictive laminate (ME composite) structure shows an equivalent magnetic noise of 0.99 nT/rt Hz at 1 Hz in the presence of a DC magnetic field of 0.1 Tesla and a great common mode noise rejection ability. A prototype magnetoelectric liver susceptometry has been demonstrated with liver phantoms. The results indicate its output signals to be linearly responsive to iron concentrations from normal iron dose (0.05 mg Fe/g liver phantom) to 5 mg Fe/g liver phantom iron overload (100X overdose). The results here open up many innovative possibilities for compact-size, portable, cost-affordable, and room-temperature operated medical systems for quantitative determinations of tissue iron.

Magnetoelectric (ME) composites have demonstrated high sensitivity for magnetic field sensor applications. Here, we report a ME laminate heterostructure consisting of magnetostrictive Tb 0.3 Dy 0.7 Fe 1.92 (Terfenol-D) alloy and piezoelectric polyvinylidene fluoride (PVDF) layers, both operated in shear mode. We show that the shear mode ME sensor exhibits a marked improved ME effect compared with the traditional ME composites operated in longitudinal and transverse piezoelectric and magnetostrictive modes using the same materials. A giant ME coefficient of 7.93 V/(cmÁOe) is obtained under a DC magnetic bias of 2300 Oe. The improved ME coefficient derives from the shear-mode heterostructure design, which allows both the Terfenol-D and PVDF to operate in shear mode that has maximum magnetoelectrical coupling coefficient. V C 2015 AIP Publishing LLC. [http://dx.Magnetic sensors with high sensitivity, compact size, and room temperature operation are of great interest for a broad range of applications. 1-3 Among them, magnetoelectric (ME) laminate sensors of magnetostrictive/piezoelectric composites bear the benefit of operating as high sensitivity magnetic sensors. 4-11 ME effect is a material phenomenon featuring the interchange between the magnetic and electric energies or signals. 12-16 Most ME laminates utilize piezoelectric longitudinal mode d 33 or transverse mode d 31 as well as longitudinal and transverse magnetostrictive modes. Wang et al. reported on a shear mode sensor with comparable sensitivity, 17 but they proposed "single layer" shear mode (only piezoelectric layer is in shear mode), as shown in Figure 1(a), the ME sensor is in L-S mode of operation (magnetostrictive layer is in longitudinal (L) mode and piezoelectric layer is in shear (S) mode). Here, we investigate a ME laminate sensor operated at shear piezoelectric and shear magnetostrictive modes (S-S mode) and demonstrate the S-S mode ME laminate sensors exhibit an improved ME response compared with that operated in the tensile piezo-and magnetostrictive modes. In this study, the improved ME coefficient was derived from the shear-mode heterostructure design, which allows both the magnetostrictive layer (Terfenol-D) and the piezoelectric polyvinylidene fluoride (PVDF) layer to operate in shear-mode that has a maximum magnetoelectrical coupling coefficient. Figure 2 presents the schematics of a S-S mode ME laminate sensors. ME laminate sensors were composed of a piezoelectric layer sandwiched between two magnetostrictive layers. Terfenol-D (ETREMA Products, IA) of 1 mm thick was used as the magnetostrictive layer and PVDF with 10 Â 2 mm 2 area and 1 mm thickness was adapted as the piezoelectric layer. Terfenol-D and PVDF were bonded by a nonconductive epoxy resin. A mechanical holder was designed to fix the ME laminate so that to achieve the shear response in both the piezo-layer and magnetostrictive layer, see Figure 3. The holder was made with alumina which has much higher elastic modulus (>100 GPa) compared with that of PVDF ($3 GPa) and is an e...