A powerful sorbent of Li+, flower-like MoS2 nanocrystals, was doped into the Spiro-OMeTAD layer for highly efficient and stable perovskite solar cells.

Natural musculoskeletal systems have been widely recognized as an advanced robotic model for designing robust yet flexible microbots. However, the development of artificial musculoskeletal systems at micro-nanoscale currently remains a big challenge, since it requires precise assembly of two or more materials of distinct properties into complex 3D micro/nanostructures. In this study, we report femtosecond laser programmed artificial musculoskeletal systems for prototyping 3D microbots, using relatively stiff SU-8 as the skeleton and pH-responsive protein (bovine serum albumin, BSA) as the smart muscle. To realize the programmable integration of the two materials into a 3D configuration, a successive on-chip two-photon polymerization (TPP) strategy that enables structuring two photosensitive materials sequentially within a predesigned configuration was proposed. As a proof-of-concept, we demonstrate a pH-responsive spider microbot and a 3D smart micro-gripper that enables controllable grabbing and releasing. Our strategy provides a universal protocol for directly printing 3D microbots composed of multiple materials.

The electron-transporting layer (ETL) plays a critical role in improving the charge extraction and suppressing the carrier recombination in planar perovskite solar cells (PSCs). Compact titanium dioxide (TiO 2 ) film is a widely used as an ETL in conventional n-i-p PSCs. However, there is still much room for improvement in the electron mobility and reducing the oxygen vacancies of the compact TiO 2 film. Herein, Pt-doped TiO 2 film with outstanding electron-transporting property and complete coverage on the substrates is reported by the authors. Pt-doping results in a tailed band level of TiO 2 , which could suppress the charge accumulation at the interface of TiO 2 -Pt/perovskite. Consequently, TiO 2 -Pt ETL based PSCs deliver a power conversion efficiency as high as 20.05% with an open-circuit voltage of 1.15 V, a fill factor of 0.75, a short-circuit current density of 23.83 mA cm À2 and remarkably alleviated hysteresis behavior.

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A carbonation model based on thermo-hygro physics is presented in this paper. Reaction of C-S-H gel was newly added to the existing model as well as calcium hydroxide reaction, and a micro-pore structure model for carbonated concrete was improved by considering volume change and surface-area increase of hydrated products. The proposed model coupled with moisture equilibrium/transport gives reasonable predictions for carbonation progresses under low and high CO 2 concentrations in a unified manner. In addition, temperature dependent parameters were installed in the system. Although detailed mechanisms should be further investigated, the proposed methodology is able to simulate carbonation phenomena under various temperature conditions.

The law of mass conservation for carbon dioxide is the governing equation to be solved in numerical analysis of the carbonation phenomenon (Ishida et al. 2007). In the new model, relationship is proposed for the temperature dependent diffusivities of carbon dioxide in water and in air, based on values in the literature (CRC 2005).

Compound eyes are unique optical imaging systems that consist of numerous separate light-sensitive units (ommatidia). Attempts have been made to produce artificial compound eyes via advanced 3D nanotechnologies. Among them, femtosecond laser direct writing (FsLDW) technology has emerged as an effective strategy due to its distinct advantages in 3D designable and high precision fabrication capability. However, the point-by-point scanning process results in a very low fabrication efficiency, limiting the practical applications of the FsLDW technology. To solve this problem, we propose a high-efficiency method for the mass production of 3D artificial compound eyes using a photopolymer template fabricated by FsLDW. The resultant 3D SU-8 compound eye templates could be used to replicate polydimethylsiloxane (PDMS) compound eyes many times (over 50 times) with a highly improved efficiency (nearly 20 times higher than the efficiency of direct fabrication using the point-by-point FsLDW). The PDMS replicas showed good focusing and imaging performances. We anticipate that this method may serve as an enabler for the mass production of 3D artificial compound eyes and promote their practical applications in the near future.

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