A novel photo-electronic hybrid-integrated synaptic device based on a 2D MoS₂ phototransistor gated by the electric-double-layer biopolymer electrolyte (sodium alginate) is proposed.

Sun, wind and tides have huge potential in providing us electricity in an environmental-friendly way. However, its intermittency and non-dispatchability are major reasons preventing full-scale adoption of renewable energy generation. Energy storage will enable this adoption by enabling a constant and high-quality electricity supply from these systems. But which storage technology should be considered is one of important issues. Nowadays, great effort has been focused on various kinds of batteries to store energy, lithium-related batteries, sodium-related batteries, zinc-related batteries, aluminum-related batteries and so on. Some cathodes can be used for these batteries, such as sulfur, oxygen, layered compounds. In addition, the construction of these batteries can be changed into flexible, flow or solid-state types. There are many challenges in electrode materials, electrolytes and construction of these batteries and research related to the battery systems for energy storage is extremely active. With the myriad of technologies and their associated technological challenges, we were motivated to assemble this 2020 battery technology roadmap.

Organic–inorganic hybrid halide perovskite nanowires (PNWs) show great potential applications in electronic and optoelectronic devices such as solar cells, field-effect transistors and photodetectors. It is very meaningful to fabricate ordered, large-area PNW arrays and greatly accelerate their applications and commercialization in electronic and optoelectronic devices. Herein, highly oriented and ultra-long methylammonium lead iodide (CH₃NH₃PbI₃) PNW array thin films were fabricated by large-scale roll-to-roll (R2R) micro-gravure printing and doctor blading in ambient environments (humility ∼45%, temperature ∼28 °C), which produced PNW lengths as long as 15 mm. Furthermore, photodetectors based on these PNWs were successfully fabricated on both silicon oxide (SiO₂) and flexible polyethylene terephthalate (PET) substrates and showed moderate performance. This study provides low-cost, large-scale techniques to fabricate large-area PNW arrays with great potential applications in flexible electronic and optoelectronic devices.

Strain sensors with good stability are vital to the development of wearable healthcare monitoring systems. However, the design of strain sensor with both duration stability and environmental stability is still a challenge. In this work, we propose an ultra-stable and washable strain sensor by embedding a coupled composite film of carbon nanotube (CNT) and Ti₃C₂T_x MXene into polydimethylsiloxane (PDMS) matrix. The composite strain sensor with embedded microstructure and uneven surface makes it conformal to skin, while the CNT/MXene sensing layer exhibits a resistance sensitive to strain. This sensor shows reliable responses at different frequencies and with long-term cycling durability (over 1,000 cycles). Meanwhile, the CNT/MXene/PDMS composite strain sensor provides the advantages of superior anti-interference to temperature change and water washing. The results demonstrate less than 10% resistance changes as the temperature rises from −20 to 80 °C or after sonication in water for 120 min, respectively. The composite sensor is applied to monitor human joint motions, such as bending of finger, wrist and elbow. Moreover, the simultaneous monitoring of the electrocardiogram (ECG) signal and joint movement while riding a sports bicycle is demonstrated, enabling the great potential of the as-fabricated sensor in real-time human healthcare monitoring.