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The applications of thermoelectric (TE) technology around room temperature are monopolized by bismuth telluride (Bi2Te3). However, due to the toxicity and scarcity of tellurium (Te), it is vital to develop...

We report an ultrasensitive label-free DNA biosensor with fully on-chip integrated rolled-up nanomembrane electrodes. The hybridization of complementary DNA strands (avian influenza virus subtype H1N1) is selectively detected down to attomolar concentrations, an unprecedented level for miniaturized sensors without amplification. Impedimetric DNA detection with such a rolled-up biosensor shows 4 orders of magnitude sensitivity improvement over its planar counterpart. Furthermore, it is observed that the impedance response of the proposed device is contrary to the expected behavior due to its particular geometry. To further investigate this difference, a thorough model analysis of the measured signal and the electric field calculation is performed, revealing enhanced electron hopping/tunneling along the DNA chains due to an enriched electric field inside the tube. Likewise, conformational changes of DNA might also contribute to this effect. Accordingly, these highly integrated three-dimensional sensors provide a tool to study electrical properties of DNA under versatile experimental conditions and open a new avenue for novel biosensing applications (i.e., for protein, enzyme detection, or monitoring of cell behavior under in vivo like conditions).

We fabricate high-performance giant magnetoresistive (GMR) sensorics on Si wafers, which are subsequently thinned down to 100 mu m or 50 mu m to realize mechanically flexible sensing elements. The performance of the GMR sensors upon bending is determined by the thickness of the Si membrane. Thus, bending radii down to 15.5mm and 6.8mm are achieved for the devices on 100 mu m and 50 mu m Si supports, respectively. The GMR magnitude remains unchanged at the level of (15.3 +/- 0.4)% independent of the support thickness and bending radius. However, a progressive broadening of the GMR curve is observed associated with the magnetostriction of the containing Ni81Fe19 alloy, which is induced by the tensile bending strain generated on the surface of the Si membrane. An effective magnetostriction value of lambda(s) = 1.7 x 10(-6) is estimated for the GMR stack. Cyclic bending experiments showed excellent reproducibility of the GMR curves during 100 bending cycles

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