Achieving high deformability in response to minimal external stimulation while maximizing human–machine interactions is a considerable challenge for wearable and flexible electronics applications. Various natural materials or living organisms consisting of hierarchical or interlocked structures exhibit combinations of properties (e.g., natural elasticity and flexibility) that do not occur in conventional materials. The interlocked epidermal–dermal microbridges in human skin have excellent elastic moduli, which enhance and amplify received tactile signal transport. Herein, we use the sensing mechanisms inspired by human skin to develop Ti3C2/natural microcapsule biocomposite films that are robust and deformable by mimicking the micro/nanoscale structure of human skinsuch as the hierarchy, interlocking, and patterning. The interlocked hierarchical structures can be used to create biocomposite films with excellent elastic moduli (0.73 MPa), capable of high deformability in response to various external stimuli, as verified by employing theoretical studies. The flexible sensor with a hierarchical and interlocked structure (24.63 kPa–1) achieves a 9.4-fold increase in pressure sensitivity compared to that of the planar structured Ti3C2-based flexible sensor (2.61 kPa–1). This device also exhibits a rapid response rate (14 ms) and good cycling reproducibility and stability (5000 times). In addition, the flexible pressure device can be used to detect and discriminate signals ranging from finger motion and human pulses to voice recognition.

A superelastic aerogel with fast shape recovery performance from large compressive strain is highly desired for numerous applications such as thermal insulation in clothing, high-sensitive sensors, and oil contaminant removal. Fabrication of superelastic cellulose nanofibrils (CNF) aerogels is challenging as the CNF can assemble into non-elastic sheet-like cell walls. Here, a dual ice-templating assembly (DITA) strategy is proposed that can control the assembly of CNF into sub-micrometer fibers by extremely low temperature freezing (-196 °C), which can further assemble into an elastic aerogel with interconnected sub-micron fibers by freezer freezing (−20 °C) and freeze drying. The CNF aerogel from the DITA process demonstrates isotropic superelastic behavior that can recover from over 80% compressive strain along both longitudinal and cross-sectional directions, even in an extremely cold liquid nitrogen environment. The elastic CNF aerogel can be easily modified by chemical vapor deposition of organosilane, demonstrating superhydrophobicity (164° water contact angle), high liquid absorption (489 g g −1 of chloroform absorption capacity), self-cleaning, thermal insulating (0.023 W (mK) −1 ), and infrared shielding properties. This new DITA strategy provides a facile design of superelastic aerogels from bio-based nanomaterials, and the derived high performance multifunctional elastic aerogel is expected to be useful for a wide-range of applications.

Wearable biosensors hold significant potential for healthcare and environmental applications, and the development of flexible and biocompatible sensing platforms for high accuracy detection of physiological biomarkers remains an elusive goal. Herein, an ultrasensitive, flexible sensor is described that is based on a 3D hierarchical biocomposite comprised of hollow, natural pollen microcapsules that are coated with a conductive graphene layer. Modular assembly of the graphene‐coated microcapsules onto an ultrathin polyethylene terephthalate layer enables a highly flexible sensor configuration with tunable selectivity afforded by subsequent covalent immobilization of antibodies against target antigens. In a proof‐of‐concept example, the biosensor demonstrates ultrahigh sensitivity detection of prostate specific antigen (PSA) down to 1.7 × 10−15m with real‐time feedback and superior performance over conventional 2D graphene‐coated sensors. Importantly, the device performance is consistently high across various bending conditions. Taken together, the results demonstrated in this work highlight the merits of employing lightweight biocomposites as modular building blocks for the design of flexible biosensors with highly responsive and sensitive molecular detection capabilities.