Computational design of ultra-robust strain sensors for soft robot perception and autonomy.

Compliant strain sensors are crucial for soft robots' perception and autonomy. However, their deformable bodies and dynamic actuation pose challenges in predictive sensor manufacturing and long-term robustness. This necessitates accurate sensor modelling and well-controlled sensor structural changes under strain. Here, we present a computational sensor design featuring a programmed crack array within micro-crumples strategy. By controlling the user-defined structure, the sensing performance becomes highly tunable and can be accurately modelled by physical models. Moreover, they maintain robust responsiveness under various demanding conditions including noise interruptions (50% strain), intermittent cyclic loadings (100,000 cycles), and dynamic frequencies (0-23 Hz), satisfying soft robots of diverse scaling from macro to micro. Finally, machine intelligence is applied to a sensor-integrated origami robot, enabling robotic trajectory prediction (<4% error) and topographical altitude awareness (<10% error). This strategy holds promise for advancing soft robotic capabilities in exploration, rescue operations, and swarming behaviors in complex environments.

Dynamic nano-imaging via a microsphere compound lens integrated microfluidic device with a 10× objective lens.

Optical microscopic imaging techniques are essential in biology and chemistry fields to observe and extract dynamic information of micro/nano-scale samples in microfluidic devices. However, the current microfluidic optical imaging schemes encounter dilemmas in simultaneously possessing high spatial and temporal resolutions. Recently, microsphere nanoscope has emerged as a competitive nano-imaging tool due to its merits like high spatial resolution, real-time imaging abilities, and cost-effectiveness, which make it a potential solution to address the aforementioned challenges. Here, a microsphere compound lens (MCL) integrated microfluidic imaging device is proposed for real-time super-resolution imaging. The MCL consists of two vertically stacked microspheres, which can resolve nano-objects with size beyond the optical diffraction limit and generate an image of the object with a magnification up to 10×. Exploiting the extraordinary nano-imaging and magnification ability of the MCL, optically transparent 100 nm polystyrene particles in flowing fluid can be discerned in real time by the microfluidic device under a 10× objective lens. Contrary to this, the single microsphere and the conventional optical microscope are incompetent in this case regardless of the magnification of objective lenses used, which demonstrates the superiority of the MCL imaging scheme. Besides, applications of the microfluidic device in nanoparticle tracing and live-cell monitoring are also experimentally demonstrated. The MCL integrated microfluidic imaging device can thus be a competent technique for diverse biology and chemistry applications.

Macromolecule conformational shaping for extreme mechanical programming of polymorphic hydrogel fibers.

Mechanical properties of hydrogels are crucial to emerging devices and machines for wearables, robotics and energy harvesters. Various polymer network architectures and interactions have been explored for achieving specific mechanical characteristics, however, extreme mechanical property tuning of single-composition hydrogel material and deployment in integrated devices remain challenging. Here, we introduce a macromolecule conformational shaping strategy that enables mechanical programming of polymorphic hydrogel fiber based devices. Conformation of the single-composition polyelectrolyte macromolecule is controlled to evolve from coiling to extending states via a pH-dependent antisolvent phase separation process. The resulting structured hydrogel microfibers reveal extreme mechanical integrity, including modulus spanning four orders of magnitude, brittleness to ultrastretchability, and plasticity to anelasticity and elasticity. Our approach yields hydrogel microfibers of varied macromolecule conformations that can be built-in layered formats, enabling the translation of extraordinary, realistic hydrogel electronic applications, i.e., large strain (1000%) and ultrafast responsive (~30 ms) fiber sensors in a robotic bird, large deformations (6000%) and antifreezing helical electronic conductors, and large strain (700%) capable Janus springs energy harvesters in wearables.