To overcome the limitation of the conventional single axis-strain sensor, we demonstrate a multidimensional strain sensor composed of two layers of prestrained silver nanowire percolation network with decoupled and polarized electrical response in principal and perpendicular directional strain. The information on strain vector is successfully measured up to 35% maximum strain with large gauge factor (>20). The potential of the proposed sensor as a versatile wearable device has been further confirmed.

State monitoring of the complex system needs a large number of sensors. Especially, studies in soft electronics aim to attain complete measurement of the body, mapping various stimulations like temperature, electrophysiological signals, and mechanical strains. However, conventional approach requires many sensor networks that cover the entire curvilinear surfaces of the target area. We introduce a new measuring system, a novel electronic skin integrated with a deep neural network that captures dynamic motions from a distance without creating a sensor network. The device detects minute deformations from the unique laser-induced crack structures. A single skin sensor decodes the complex motion of five finger motions in real-time, and the rapid situation learning (RSL) ensures stable operation regardless of its position on the wrist. The sensor is also capable of extracting gait motions from pelvis. This technology is expected to provide a turning point in health-monitoring, motion tracking, and soft robotics.

instruments, and wearable assistive devices, but which mostly are restricted to discrete motions. However, soft robotics with entirely soft bodied system often solve difficulties in conventional rigid robots by overcoming their constraints, exceeding the performances and creating new applications. [1][2][3] Therefore, these soft machines have already taken many roles in industrial processing, automation, marine engineering, etc. [4][5][6] Technological advances in robots and wearable devices are closely connected to optical and mechanical compliance depending on their use. By taking advantages of recent advancements in transparent actuators and sensors, combining their soft and stretchy mechanical compliance with optically transparent property affords to create a new class of soft robotics, which can be referred to as an imperceptible soft robotics (ISR). As shown in Figure 1, systematic diagram of imperceptible soft robotics describes that ISR will mainly consist of transparent systems and camouflage skin. Transparent systems embrace optically transparent soft actuators and sensors in order to build mechanically interactive robotics that are rarely seen by others. As a supportive component, camouflage skin aims to provide for transparent systems to adapt in natural environment or humans for undercover operation and safe user-friendly interactions. This new conception of imperceptible soft robotic system that exhibits optically transparent interface or visually imperceptions through camouflage skin provides new functionalities over ones without such properties. Imperceptions of an assistive wearable device can be crucially important in wearer's daily life. Mechanically compliant and visually imperceptive human assistive device can serve the user's rehabilitation process or support disabled parts in the body without discomfort, altering biomechanics, and obstructive to others. [7] In a similar fashion, robotic prosthetics that requires soft sensing capability of motherly touch for caring babies demand integrated sensors and actuators to be imperceptible. [8] Tactile sensation with an implementation of ISR delivering information to user in private also possesses a wide range of possibility in virtual/augmented reality for human-machine interface and smart-living environment. [9][10][11][12] Undercover mission enabled by disguising into nature through optical transparency or environmentally skin will also be achieved by imperceptibleThe advent of soft robotics has led to great advancements in robots, wear ables, and even manufacturing processes by employing entirely soft-bodied systems that interact safely with any random surfaces while providing great mechanical compliance. Moreover, recent developments in soft robotics involve advances in transparent soft actuators and sensors that have made it possible to construct robots that can function in a visually and mechanically unobstructed manner, assisting the operations of robots and creating more applications in various fields. In this aspect, imperceptible soft robo...

Development of an artificial camouflage at a complete device level remains a vastly challenging task, especially under the aim of achieving more advanced and natural camouflage characteristics via high-resolution camouflage patterns. Our strategy is to integrate a thermochromic liquid crystal layer with the vertically stacked, patterned silver nanowire heaters in a multilayer structure to overcome the limitations of the conventional lateral pixelated scheme through the superposition of the heater-induced temperature profiles. At the same time, the weaknesses of thermochromic camouflage schemes are resolved in this study by utilizing the temperature-dependent resistance of the silver nanowire network as the process variable of the active control system. Combined with the active control system and sensing units, the complete device chameleon model successfully retrieves the local background color and matches its surface color instantaneously with natural transition characteristics to be a competent option for a next-generation artificial camouflage.

Pressure-sensitive touch panels can measure pressure and location (3D) information simultaneously and provide an intuitive and natural method for expressing one’s intention with a higher level of controllability and interactivity. However, they have been generally realized by a simple combination of pressure and location sensor or a stylus-based interface, which limit their implementation in a wide spectrum of applications. Here, we report a first demonstration (to our knowledge) of a transparent and flexible 3D touch which can sense the 3D information in a single device with the assistance of functionally designed self-generated multiscale structures. The single 3D touch system is demonstrated to draw a complex three-dimensional structure by utilizing the pressure as a third coordinate. Furthermore, rigorous theoretical analysis is carried out to achieve the target pressure performances with successful 3D data acquisition in wireless and wearable conditions, which in turn, paves the way for future wearable devices.