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In nature, animals or plants often use soft organs to move and hunt. Research works on bioinspired materials and devices have attracted more and more interest as which show the potential for future intelligent robots. As key components of soft robots, biomimetic soft actuators are adapted to greater requirements for convenient, accurate, and programmable controlling robots. Here, a class of materials and processing routes of ultrathin actuators are reported for bioinspired piecewise controllable soft robots, where the actuators associate with thermal‐responsible soft silicone thin film with thickness as thin as 45 µm and electrically driven by well mechanical designed metallic thin film electrodes. Multiple electrodes in the robots in charge of individual segments control allow the soft robots exhibiting similar functionalities of animals or plants (for example, imitating the tongue of a reptile, such as chameleon to hunt moving preys, and mimicking vines to tightly wind around objects). These bionic results in the soft robots demonstrate their advantages in precise and flexible operation, which provides a good reference for the future research of intelligent soft actuators and robots. [ABSTRACT FROM AUTHOR]

Development of unconventional technologies for wireless collection and analysis of quantitative, clinically relevant information on physiological status is of growing interest. Soft, biocompatible systems are widely regarded as important because they facilitate mounting on external (e.g., skin) and internal (e.g., heart and brain) surfaces of the body. Ultraminiaturized, lightweight, and battery-free devices have the potential to establish complementary options in biointegration, where chronic interfaces (i.e., months) are possible on hard surfaces such as the fingernails and the teeth, with negligible risk for irritation or discomfort. Here, the authors report materials and device concepts for flexible platforms that incorporate advanced optoelectronic functionality for applications in wireless capture and transmission of photoplethysmograms, including quantitative information on blood oxygenation, heart rate, and heart rate variability. Specifically, reflectance pulse oximetry in conjunction with near-field communication capabilities enables operation in thin, miniaturized flexible devices. Studies of the material aspects associated with the body interface, together with investigations of the radio frequency characteristics, the optoelectronic data acquisition approaches, and the analysis methods capture all of the relevant engineering considerations. Demonstrations of operation on various locations of the body and quantitative comparisons to clinical gold standards establish the versatility and the measurement accuracy of these systems, respectively. [ABSTRACT FROM AUTHOR]

Thin, soft, skin‐like electronics capable of transforming body mechanical motions to electrical signals have broad potential applications in biosensing and energy harvesting. Forming piezoelectric materials into flexible and stretchable formats and integrating with soft substrate would be a considerable strategy for this aspect. Here, a skin‐integrated rubbery electronic device that associates with a simple low‐cost fabrication method for a ternary piezoelectric rubber composite of graphene, lead zirconate tinanate (PZT), and polydimethylsiloxane (PDMS) is introduced. Comparing to the binary composite that blend with PZT and PDMS, the graphene‐embedded ternary composite exhibits a significant enhancement of self‐powered behavior, with a maximum power density of 972.43 µW cm−3 under human walking. Combined experimental and theoretical studies of the graphene‐embedded PZT rubber allow the skin‐integrated electronic device to exhibit excellent mechanical tolerance to bending, stretching, and twisting for thousands of cycles. Customized device geometries guided by optimized mechanical design enable a more comprehensive integration of the rubbery electronics with the human body. For instance, annulus‐shape devices can perfectly mount on the joints and ensure great power output and stability under continuous and large deformations. This work demonstrates the potential of large‐area, skin‐integrated, self‐powered electronics for energy harvesting as well as human health related mechanical sensing. [ABSTRACT FROM AUTHOR]

A concept for millimeter‐scale, battery‐free sensors for measuring heart rate and blood oxygenation in presented by J. A. Rogers and co‐workers on page 1604373. Reflectance pulse oximetry data is devoid of motion artifacts when obtained by wireless near‐field communication from various body locations. The concept bears excellent potential for be employed in flexible devices. Image taken by Philipp Gutruf. [ABSTRACT FROM AUTHOR]

Limited electrode size with high electrochemical performance and reliability of modified materials are two of the main concerns for flexible neural electrodes in recent years. Here, an effective fabrication method of enhanced micro-scale wrinkles based on oil-pretreated hyperelastic substrates (PDMS and Ecoflex) is proposed for the application of microelectrode biosensors. Compared to pre-stretching or compressing methods, this approach has better advantages including compatibility with MEMS processes on wafer and easy replication. Wrinkled gold microelectrodes exhibit superior electrochemical properties than the flat one, and no crack or delamination occurs after electroplating PEDOT:PSS and platinum black on wrinkled microelectrodes. Cyclic voltammetry (CV) scanning for 2500 times is performed to investigate adhesion and stability of modified materials. For the modified microelectrodes, no significant change is observed in charge storage capacity (CSC) and impedance at 1 kHz, whereas PEDOT:PSS coated flat microelectrodes appears delamination. Ultrasonication and cycling forces are also conducted on modified microelectrodes, which demonstrates little influence on the wrinkled ones. Flexible wrinkled microelectrodes are further verified by in-vivo ECoG recordings combined with optogenetics in mice. These results highlight the importance of micro-structure in neural electrode design and tremendous application potentials in flexible electronics. • A novel fabrication method of microelectrode biosensors with enhanced micro-scale wrinkles was proposed for the first time. • The modified enhanced wrinkled microelectrodes exhibited stronger stability than the flat ones, especially for PEDOT:PSS. • In-vivo ECoG signals combined with optogenetics in mice showed reliable recording ability of the proposed microelectrodes. [ABSTRACT FROM AUTHOR]