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To diversify the motion modes of multifunctional soft robots capable of shape programming, we fabricate a biomimetic and programmable Ti3C2Tx MXene/low-density polyethylene (LDPE) bilayer actuator by spraying an aqueous dispersion of MXenes onto a plasma-activated LDPE film, followed by optimal thermal regulations. Because of the eminent light absorption and photothermal/electrothermal features of MXenes and the extremely mismatched thermal expansion coefficients between the two layers, the MXene/LDPE actuator can be sensitively driven by many stimuli of near-infrared light, electricity, and heat. The initial configuration of the bilayer actuator can be programmed by tuning the thermal regulation temperature, thereby assembling multiple actuation units to achieve biomimetic functions, such as artificial iris, mechanical arms, and flying birds. More importantly, in virtue of free shape cutting and programmable configuration, the MXene/LDPE bilayer actuator can perform untethered locomotion including crawling, rolling, and sailing. The soft robots can not only move on the ground in different forms but also sail on water along any designated routes and complete the surface cargo transportation driven by a near-infrared laser via the photothermal Marangoni effect. The shape-programmable methodology for the three amphibious motion modes lays foundations for wide applications of the MXene-based soft robots.

Smart electromagnetic interference shielding materials with multi-responsive actuation capability are greatly required for next-generation electronics. Here, a flexible, multi-responsive and electrically conductive graphene oxide (GO)/MXene Janus film is fabricated by a scalable sequential vacuum filtration technique. The hydrophilic feature of both GO and MXene enable the formation of Janus-structured films with strong obscure interfaces, achieving multiple stimuli responses (humidity, light, and electricity) and high electromagnetic interference (EMI) shielding performances. The film actuator can be largely bent from −270° to 460° within a wide relative humidity range and exhibits sensitive and fast actuation responses to near-infrared light and electricity. Additionally, the Janus film can also act as the smart switch and soft walking robot. Furthermore, the presence of the highly conductive MXene layer provides the film with attractive EMI shielding effectiveness of 40 dB at a small thickness of 1.5 μm. As a proof-of-concept, a smart EMI shielding curtain and a stimuli-responsive EMI shielding system are assembled using the Janus film. The smart EMI shielding film could effectively tune signal transmission by stimuli to meet specific shielding needs in intelligent electronics and devices.