Stretchable electronics enable seamless integration of wearables with the human body, thereby creating new opportunities in biomedical applications. Miniaturized multilayer stretchable printed circuit boards are key for achieving high functional density circuits with minimal footprint. However, current microfabrication technologies struggle with simultaneously achieving tissue-like softness (<<1 MPa), high resolution and low sheet resistance. This study demonstrates a scalable printing method that enables ultra-soft (<0.4 MPa) stretchable conductors (>300% strain) with high-resolution (<2.5 µm width) and high aspect-ratio tracks (>1) connected by ultra-fine (20 µm) vertical-interconnect-access (VIA) for multi-layered configurations. The method is based on stencil printing into laser-defined bio-masks comprising the abundant biopolymer lignin, thereby achieving printing capabilities beyond conventional methods in a sustainable manner. Based on the unique capabilities, a miniaturized multilayer ultra-soft wireless near-field-communication temperature logger is developed. Laser-defined printing can pave the way for the next generation of ultra-soft miniaturized wearables.

An ISM band sectorial compact antenna working at 868 MHz is presented in this paper. The antenna is designed to have very low perturbations in terms of radiation pattern, bandwidth and input impedance when mounted on different environments at the rear (i.e. wood, plastic or metal support). Furthermore, the PIFA topology of the antenna allows an easy matching either to a 50 Ohm input impedance for IoT/LoRA applications or to a complex impedance value for RFID applications with the help of a simple matching circuit. 

Screen printed piezoelectric polyvinylidene fluoride?trifluoro ethylene (PVDF?TrFE)-based sensors laminated between glass panes in the temperature range 80?110?°C are presented. No degradation of the piezoelectric signals is observed for the sensors laminated at 110?°C, despite approaching the Curie temperature of the piezoelectric material. The piezoelectric sensors, here monitoring force impact in smart glass applications, are characterized by using a calibrated impact hammer system and standardized impact situations. Stand-alone piezoelectric sensors and piezoelectric sensors integrated on poly(methyl methacrylate) are also evaluated. The piezoelectric constants obtained from the measurements of the nonintegrated piezoelectric sensors are in good agreement with the literature. The piezoelectric sensor response is measured by using either physical electrical contacts between the piezoelectric sensors and the readout electronics, or wirelessly via both noncontact capacitive coupling and Bluetooth low-energy radio link. The developed sensor concept is finally demonstrated in smart window prototypes, in which integrated piezoelectric sensors are used to detect break-in attempts. Additionally, each prototype includes an electrochromic film to control the light transmittance of the window, a screen printed electrochromic display for status indications and wireless communication with an external server, and a holistic approach of hybrid printed electronic systems targeting smart multifunctional glass applications.

In this work we report the design and implementation of a very high speed retroreflective free space communication system between a ground station and a commercial unmanned aerial vehicle (UAV). The system uses a pixelated electro-absorption modulator (EAM) modulating retroreflector (MRR) to establish a data link operating at 500 Mbps at a range of 560 m and a bit error rate (BER) of 7.610-4. The MRR provides an effective aperture of 11mm and full field of view (FFOV) of 6.4. To the best of our knowledge, this is the fastest demonstration of an outdoor link of this type. In this paper the design and implementation of the system is described, as well as results from experimental trials.

In this letter, we present the design and implementation of a pixelated electro-absorption modulator-based modulating retroreflector (MRR) for high-speed optical wireless communications. The modulator is based on a multiple quantum well structure embedded in an asymmetric Fabry-Perot cavity. This MRR was used in an outdoor link, operating at 150 Mb/s with a bit error rate (BER) of 1.22 × 10^-6 at a range of 200 m. The system was also tested in laboratory-controlled conditions achieving a data rate of 200 Mb/s with a BER of 2 × 10^-4. To the best of our knowledge, this is the fastest retroreflective free-space optics demonstration in both the indoor and outdoor environments.

The satellite market is shifting towards smaller (micro and nanosatellites), lowered mass and increased performance platforms. Nanosatellites and picosatellites have been used for a number of new, innovative and unique payloads and missions. This trend requires new concepts for a reduced size, a better performance/weight ratio and a reduction of onboard power consumption. In this context, disruptive technologies, such as laser-optical communication systems, are opening new possibilities. This paper presents the C3PO1 system, "advanced Concept for laser uplink/ downlink CommuniCation with sPace Objects", and the first results of the development of its key technologies. This project targets the design of a communications system that uses a ground-based laser to illuminate a satellite, and a Modulating Retro-Reflector (MRR) to return a beam of light modulated by data to the ground. This enables a downlink, without a laser source on the satellite. This architecture suits well to small satellite applications so as high data rates are potentially provided with very low board mass. C3PO project aims to achieve data rates of 1Gbit/s between LEO satellites and Earth with a communication payload mass of less than 1kilogram. In this paper, results of the initial experiments and demonstration of the key technologies will be shown.

Ahighly integrated silicon platform(Hi-Mission) for high frequency applications is introduced.This platformutilizes heterogeneous Multi-Chip Module-Deposited (MCM-D) technology with integrated passive devices together with silicon GaAs Monolithic Microwave Integrated Circuit (MMIC) technology developed for the automotive Ultra Wide B(UWB) radar (short-range radar) frequency bfrom 77 to 81 GHz. Developments are described in the area ofMCM-D process development,MMIC, integrated phased array antenna,module design, assembly process development. The demonstrator is composed of two test vehicles designed for conducted radiated measurements, respectively. Test results are presented at the component module level._x000D_