Anisotropic hydrogels with a hierarchical structure can mimic biological tissues, such as neurons or muscles that show directional functions, which are important factors for signal transduction and cell guidance. Here, we report a mussel-inspired approach to fabricate an anisotropic hydrogel based on a conductive ferrofluid. First, polydopamine (PDA) was used to mediate the formation of PDA-chelated carbon nanotube-Fe3O4 (PFeCNT) nanohybrids and also used as a dispersion medium to stabilize the nanohybrids to form a conductive ferrofluid. The ferrofluid can respond to an orientated magnetic field and be programed to form aligned structures, which were then frozen in a hydrogel network formed via in situ free-radical polymerization and gelation. The resulted hydrogel shows directional conductive and mechanical properties, mimicking an oriented biological tissue. Under external electrical stimulation, the orientated PFeCNT nanohybrids can be sensed by the myoblasts cultured on the hydrogel, resulting in the oriented growth of cells. In summary, the mussel-inspired anisotropic hydrogel with its aligned structural complexity and anisotropic properties together with the cell affinity and tissue adhesiveness is a potent multifunctional biomaterial for mimicking oriented tissues to guide cell proliferation and tissue regeneration.

The anomalous Hall effect, observed in conducting ferromagnets with broken time-reversal symmetry, offers the possibility to couple spin and orbital degrees of freedom of electrons in ferromagnets. In addition to charge, the anomalous Hall effect also leads to spin accumulation at the surfaces perpendicular to both the current and magnetization direction. Here, we experimentally demonstrate that the spin accumulation, subsequent spin backflow, and spin–charge conversion can give rise to a different type of spin current-related spin current related magnetoresistance, dubbed here as the anomalous Hall magnetoresistance, which has the same angular dependence as the recently discovered spin Hall magnetoresistance. The anomalous Hall magnetoresistance is observed in four types of samples: co-sputtered (Fe1−xMnx)0.6Pt0.4, Fe1−xMnx/Pt multilayer, Fe1−xMnx with x = 0.17–0.65 and Fe, and analyzed using the drift-diffusion model. Our results provide an alternative route to study charge–spin conversion in ferromagnets and to exploit it for potential spintronic applications.

Cs 2 AgBiBr 6 -and Cs 3 Bi 2 Br 9 -alternatives) photocatalysts in the long-wavelength range of visible light (Figure 4d; Table S2, Supporting Information), [49][50][51][52][53][54][55][56][57][58][59][60][61][62][63] and is expected to be further improved by integrated with suitable surface active sites.

fascinating spintronic effects are spinorbit torque (SOT) [10] and spin Hall magnetoresistance (SMR) [11] in ferromagnet (FM)/heavy metal (HM) bilayers. Taking advantage of these intriguing effects, recently we have demonstrated an AMR/ SMR sensor (hereafter we call it SMR sensor considering the fact that SMR is dominant) with the SOT effective field as the built-in linearization mechanism, [12,13] which effectively replaces the sophisticated linearization mechanism employed in conventional MR sensors. [14] However, as the sensors were driven by DC current, we still faced the same issues as commercial AMR sensors, that is, DC offset and domain motion induced noise. Here, we demonstrate that, by introducing AC excitation, we achieved an all-in-one magnetic sensor which embodies multiple functions of AC excitation, domain stabilization, rectification detection, and DC offset cancellation, and importantly, all these features are realized in a simplest possible structure which consists of only an ultrathin NiFe/Pt bilayer. Such kind of integrated AC excitation and rectification are not possible in conventional AMR sensors. The sensors are essentially free of DC offset with negligible hysteresis and low noise (with a detectivity of 1 nT Hz −1/2 at 1 Hz). Through a few proof-ofconcept experiments, we show that these sensors promise great potential in a variety of low-field sensing applications including navigation, angle detection, and wearable electronics.When a charge current passes through a ferromagnet (FM)/ heavy metal (HM) bilayer, it brings about two novel spintronic effects, namely, the SOT [10] and SMR. [11] Both SOT and SMR share the same origin, i.e., the spin current generated in the HM layer by the spin Hall effect (SHE). [15][16][17] The spin current is transverse to the charge current and therefore causes spin accumulation at both the FM/HM interfaces and side surfaces of HM. The spin accumulation at the interfaces is partially absorbed by the FM layer, resulting in a torque on its magnetization, i.e., the SOT. Although the exact mechanism still remains debatable, both Rashba [18] and SHE [15][16][17] are commonly believed to play a crucial role in giving rise to the SOT in FM/ HM bilayers. There are two types of SOTs, one is field-like (FL) and the other is damping-like (DL); the latter is similar to spin transfer torque. Phenomenologically, the two types of torques can be modelled by