Graphene is hailed as an ideal material for spintronics due to weak intrinsic spin-orbit interaction that facilitates lateral spin transport and tunability of its electronic properties [1-3], including a possibility to induce magnetism in graphene [4-9]. Another promising application of graphene is related to its use as a spacer separating ferromagnetic metals (FMs) in vertical magnetoresistive devices [10-20], the most prominent class of spintronic devices widely used as magnetic sensors. In particular, few-layer graphene was predicted [10-12] to act as a perfect spin filter. Here we show that the role of graphene in such devices (at least in the absence of epitaxial alignment between graphene and the FMs) is different and determined by proximity-induced spin splitting and charge transfer with adjacent ferromagnetic metals, making graphene a weak FM electrode rather than a spin filter. To this end, we report observations of magnetoresistance (MR) in vertical Co-graphene-NiFe junctions with 1 to 4 graphene layers separating the ferromagnets, and demonstrate that the dependence of the MR sign on the number of layers and its inversion at relatively small bias voltages is consistent with spin transport between weakly doped and differently spin-polarized layers of graphene. The proposed interpretation is supported by the observation of an MR sign reversal in biased Co-graphene-hBN-NiFe devices and by comprehensive structural characterization. Our results suggest a new architecture for vertical devices with electrically controlled MR. Following the successful development of graphene-based lateral spintronic structures [1-8], the implementation of graphene as a spacer in vertical magnetic tunnel junctions (MTJ) has become a subject of intense interest [13-20]. Up to now, theoretical proposals [10-12] for graphene's role in MTJs focused on the so-called 'K-point spin filtering' expected in ideally lattice-matched single-crystalline ferromagnet-graphene-ferromagnet (FM-G-FM) structures and attributed to matching spin-polarized bands in the ferromagnet and the electronic states in the graphene treated as a tunnelling barrier. This mechanism was also used to interpret the MR sign inversion observed in conventional Ni-Al 2 O 3 -Co [13] and Ni-MgO-Co [14] tunnel junctions where the Ni electrode was passivated by CVD grown (epitaxial) mono-[13] or few-layer [14] graphene. However, despite several attempts,

Breast implants are still manufactured using outdated techniques and have changed little since their inception in the 1960's. Breast implants can cause a medical condition, capsular contracture which often results in disfigurement, pain, implant removal and further surgery. This condition is due to the body's reaction to these breast implants. This article describes the successful development and testing of a novel breast implant surface inspired by the native shapes present in breast tissue. Results show that this novel implant surface is capable of reducing the negative reaction of human cells to these surfaces which may help reduce capsular contracture formation. This work represents the first steps in producing a biocompatible breast implant.

Due to a very high carrier concentration and low band gap, graphene based self-switching diodes do not demonstrate a very high rectification ratio. Despite that, it takes the advantage of graphene's high carrier mobility and has been shown to work at very high microwave frequencies. However, the AC component of these devices is hidden in the very linear current-voltage characteristics. Here, we extract and quantitatively study the device capacitance that determines the device nonlinearity by implementing a conformal mapping technique. The estimated value of the

It has been shown that graphene can demonstrate ballistic transport at room temperature. This opens up a range of practical applications that do not require graphene to have a band gap, which is one of the most significant challenges for its use in the electronics industry. Here, the very latest high mobility graphene (>100,000 cm 2 V À1 s À1 ) fabrication techniques will be demonstrated so that one such device, called the triangular ballistic rectifier (TBR), can be characterised. The TBR is a four-terminal device with a triangular anti-dot at their intersection; two sides of the triangle are positioned and angled such that ballistic carriers from the two input electrodes are redirected like billiard balls to one of the two output contacts irrespective of the instantaneous polarity of the input. A responsivity of 2400 mV mW À1 is demonstrated at room temperature from a low-frequency input signal. The ballistic nature of the device is justified and explained in more detail with lowtemperature measurements.