Printed electronics offer a breakthrough in the penetration of information technology into everyday life. The possibility of printing electronic circuits will further promote the spread of the Internet of Things applications. Inks based on graphene have a chance to dominate this technology, as they potentially can be low cost and applied directly on materials like textile and paper. Here we report the environmentally sustainable route of production of graphene ink suitable for screen-printing technology. The use of non-toxic solvent Dihydrolevoglucosenone (Cyrene) significantly speeds up and reduces the cost of the liquid phase exfoliation of graphite. Printing with our ink results in very high conductivity (7.13 × 104 S m−1) devices, which allows us to produce wireless connectivity antenna operational from MHz to tens of GHz, which can be used for wireless data communication and energy harvesting, which brings us very close to the ubiquitous use of printed graphene technology for such applications.

Ultrafine particulate aerosols less than 100 nm diffuse randomly in the air and are hazardous to the environment and human health. However, no technical standards or commercial products are available for filtering particle sizes under 100 nm yet. Here, we report the development of a porous poly­(l-lactic acid) (PLLA) nanofibrous membrane filter with an ultra-high specific surface area via electrospinning and a post-treatment process. After PLLA fibres were electrospun and collected, they were treated by acetone to generate a blossoming porous structure throughout each individual fibre. Characterizations of morphology, crystallinity, and mechanical and thermal properties demonstrated that the porous structure can be attributed to the nonsolvent-induced spinodal phase separation during electrospinning and solvent-induced recrystallization during post treatment. The blossoming porous structure with high specific surface area contributed to excellent filtration efficiency (99.99%) for sodium chloride (NaCl) ultrafine aerosol particles (30–100 nm) with a low pressure drop (110–230 Pa). Notably, under 7.8 cm/s air flow rate, the membrane samples performed better for filtering smaller-sized aerosol particles than the larger ones when evaluated by the quality factor (0.07). Finally, this finding demonstrates that the electrospun membrane with a hierarchical pore structure and high specific surface area hold great potential in applications as air-filtering materials.

Screen-printed graphene near field communication (NFC) tag antenna is integrated with inkjet-printed WS2 photodetector on paper substrate to fabricate battery-free wireless photosensor. A sequential multi-stack printing is employed for the wireless photosensor fabrication: the NFC tag antenna is first screen-printed with graphene conductive ink and then the photodetector is inkjet-printed with transition metal dichalcogenides (TMDs) WS2 ink as photoactive component. High responsivity and sensitivity are observed for the WS2 photodetector, which acts as photoactive thermistor of the NFC sensor IC chip. The highly conductive graphene nanoflakes ink enables the screen-printed graphene NFC tag antenna to withdraw sufficient power wirelessly from the reader to power the sensor IC chip. This work demonstrates a prospective approach to manufacture 2D materials enabled electronics where the electronic circuits (normally having a large size) can be realized by mass production screen printing and the sensing component (normally having a small size) can be produced by inkjet printing, enabling low cost and simple fabrication methods, compatible with flexible substrates such as paper.

A battery free wearable sensing device with temperature and sweat sensors embedded into and powered by a smart textile NFC antenna available for both NFC readers and NFC enabled smart phones, which can take part in various medical applications such as daily healthcare, fever detection and wound healing monitoring. Take-Home Messages  In this manuscript, body temperature and sweat sensors are integrated with a textile NFC antenna, which eliminates the need for external batteries and realizes real-time wireless monitoring.  This paper has presented design, fabrication implementation, measurements and real-life applications of smart textile NFC antennas and a battery-free wireless NFC body temperature and sweat sensing device, aiming for truly ubiquitous wireless health and wellbeing monitoring.  The proposed device targets at body temperature and sweat loss monitoring for daily healthcare, systemic hyperthermia from fever, sweating symptoms caused by various kinds of infection, inflammation and trauma and wound healing monitoring.  Different from conventional battery enabled and wire connected sensors, the significance of this work is by applying textile NFC as a communication interface as well as a wireless power harvester, battery-free realtime body temperature and sweat monitoring has been realized simultaneously.  Apart from the device itself, an App has also been developed on Android system for the sensor data to be accessed by smart phones.

Wearable e-textile Near Field Communication (NFC) RFID antennas fully integrated with garments using embroidery techniques, which enables everyday clothing to become connective to wireless communication systems, is presented. The e-textile wearable antennas have been designed through full electromagnetic wave simulation based on the electrical properties of conductive treads and textile substrates at the High Frequency (HF) band, allocated for NFC wireless communications. The e-textile wearable NFC antenna performance under mechanical bending as well as human body effects have been experimentally studied and evaluated; the antennas can operate under significantly bending angle and body effects attributed to its broad operating bandwidth. This is highly desirable and distinguished to conventional NFC antennas; the proposed e-textile wearable NFC antennas can be placed almost any place on clothes and still capable to communicate at desired operating frequency of 13.56MHz. The maximum read range of the e-textile wearable NFC tags are measured to be around 5.6cm, being compatible to typical commercially available metallic NFC tags. The e-textile wearable NFC tags can lead to numerous potential applications such as information exchange, personal security, health monitoring and IoTs.