decisive drawbacks are (i) only a low to moderate level of scalability, (ii) restrictions for the size as well as the material of the substrate due to high-vacuum processes at elevated temperatures, iii) a lack of mechanical flexibility and iv) optical transparency.A few of these obstacles have been overcome with the emergence of novel materials such as carbon nanotubes (CNTs), graphene, [2] graphene oxide, [3] poly (3,4ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS), [4] metal nanomeshes, [5] silver-coated polyester films (AgHT), [6] silver flakes, [7] silver nanoparticles, [8] copper oxide nanoparticles [9] as well as metal nanowires. [10,11] For the majority of these materials, scalable and high-yield synthesis protocols or fabrication techniques exist and these materials can potentially be deposited at almost arbitrary scale and under ambient conditions. Due to the cost-effectiveness, the ease-of-processing and the scalability, deposition methods such as inkjet printing, [12] direct laser writing, [13] spray coating [14] or screen printing [15] have become increasingly popular over the last years and raised academic and industrial interest.A high optical transparency of the deposited films is already a requirement for numerous antenna applications including solar cells, [16] sun shields on satellites, [17] radio-identification tags (RFIDs), [18][19][20][21] smart glasses, [22] bandstop filters to reduce the interference from wireless local area networks (WLANs) [23] as well as for energy harvesting. [24,25] Due to this broad application spectrum and the commercialization potential, notable technology companies including the so-called Big Techs, have recently filed several patents related to transparent conductive films and their use for antennas. [26][27][28] The conducting and transparent films presented in this work were made of a commercially available silver nanowire (AgNW)-based screen print paste. The use of screen printed AgNWs for antennas has already been reported in 2014 by Song et al. [29] However, in that work, the antenna films were fully opaque, which is a criterion for exclusion in many applications. In this work, as transparent electrode (TE) material, AgNWs were selected since this material is currently considered as the most promising alternative to the prevailing TE material, i.e., indium tin oxide (ITO), [30] with regard to the electro-optical performance as well as the chemical and the mechanical stability. [31] The antennas presented in this work show a highThe advent of mobile communication has made antennas omnipresent. Conventional methods of antenna manufacturing cannot address the growing demands for novel applications requiring transparent and flexible antennas. In this paper, transparent silver nanowire films are studied with respect to their highfrequency properties. Transparent silver nanowire (AgNW)-based antennas that are screen printed onto flexible polyethylene terephthalate (PET) substrate are reported. Transparent films with a low sheet resistance of 8.5 Ω sq −...

Spinal cord injury (SCI) is a yet untreatable neuropathology that causes severe dysfunction and disability. Cell-based therapies hold neuroregenerative and neuroprotective potential but, although being studied in SCI patients for more than two decades, long-term efficacy and safety remain unproven, and it is still debated which cell types result in higher neurological and functional recovery. In a comprehensive scoping review of 142 reports and registries of SCI cell-based clinical trials, we addressed the current therapeutical trends and critically analyzed the strengths and limitations of the studies. Schwann cells, olfactory ensheathing cells (OECs), macrophages, and various types of stem cells (SCs) have been tested, as well as combinations of these and other cells. A comparative analysis between the reported outcomes of each cell type was performed, according to gold-standard efficacy outcome measures like the ASIA impairment scale (AIS), motor and sensory scores. Most of the trials were in the early phases of clinical development (phase I/II), involved patients with complete chronic injuries of traumatic etiology, and did not display a randomized comparative control arm. Bone marrow SCs and OECs were the mainly used cells, while open surgery and injection were the most common methods, delivering cells into the spinal cord or submeningeal spaces. Transplantation of support cells, such as OECs and Schwann cells, resulted in the highest AIS grade conversion rates (improvements in ∼40% of transplanted patients), which surpasses the spontaneous improvement rate expected for complete chronic SCI patients within one-year post-injury (5-20%). Some stem cells, such as peripheral blood-isolated ones (PB-SCs) and Neural SCs (NSCs) and also present potential for improving patients’ recovery. Complementary treatments, particularly post-transplantation rehabilitation regimes, may highly contribute to neurological and functional recovery. However, unbiased comparisons between the tested therapies are difficult to draw, given the great heterogeneity of the design and outcome measures used in the SCI cell-based clinical trials, and how these are reported. It is therefore crucial to standardize these trials when aiming for clinical evidence-based conclusions of higher value.

Abstract. UHF RFID tags are nowadays widely and successfully implemented in many distinct applications, but unfortunately the traditional production process and incorrect disposal of such devices have a negative impact on the environment. In this work silver and gold nanoparticle inks were printed by a consumer inkjet printer on eco-friendly substrates like paper and PET in order to make the manufacturing process less harmful to the ecosystem. A dipole antenna with matching loop was designed for the RFID chip EM4325 from EM Microelectronics, which has an integrated temperature sensor, at the frequency of 866 MHz. Based on this design, simulations of the greener tags are presented and compared as a proof of concept, without optimizing the designs at first for the different materials. The printings with silver (unlike the gold) were conductive with self-sintering. IPL sintering was conducted to reduce the sheet resistance from the silver ink and to turn the gold ink conductive. First S11 parameter and read distance measurements are shown as well as the simulations with the optimized antenna designs.

The use of nonmetallic conductor materials in RF applications has recently become a highlighted issue when it comes to sustainability in the electronics industry, mainly because of the waste problems associated with heavy metals and the necessity of reducing and managing them. The replacement of metal in functional applications such as in electronics is therefore very important. Among these new materials, organic conductors are of great interest since they are, in general, biocompatible and biodegradable, allowing for the disposal of electronic devices, which reduces the negative environment impact caused by electronics waste. In this work, PEDOT:PSS and Carbon are investigated. Since these materials are available as conducting pastes or inks, the production of conducting patterns by printing techniques such as screen printing is possible, which can make the process less harmful to the environment, since it permits the use of organic substrates such as paper. In order to investigate the feasibility of these materials for RF signal transmission, screen printed PEDOT:PSS and Carbon transmission lines have been designed, fabricated and characterized. Results regarding conductivity, thickness, electric permittivity and S21 parameter are presented and will serve as a foundation for the development of further reaching applications utilizing organic materials.