Technological advancements drive demand for smart, flexible, and sustainable devices capable of integration into daily life. Pressure sensors, particularly those utilizing halide perovskites, face key challenges in sensitivity, stability, and integration with soft systems. This study focuses on the investigation of quasi two-dimensional (2D) perovskite pressure sensors, where the perovskite is embedded within a Polyvinylidene fluoride (PVDF) polymer matrix, and protected by Polydimethylsiloxane (PDMS) polymer layer. The improvement in the performance of the pressure sensors is achieved through the optimization of solvent composition, perovskite:PVDF ratio, and the thickness of the PDMS layer, with a deep understanding of the morphological structure's influence on piezoelectric properties. Our perovskite layer achieves a high piezoelectric coefficient (d33) of 31.26 pm/V, surpassing previously reported values for halide perovskites. Unlike previous studies, we systematically investigate the correlation between PDMS thickness and piezoelectric response, identifying a critical thickness threshold (~23 μm) beyond which sensing is suppressed. The devices demonstrate pressure sensitivity in the absence of any external power source and maintaining reliable performance for 1,000 cycles and up to 60 days in ambient conditions. Successful integration of the sensors into soft robotic gripper while also demonstrating sensitivity to various weights highlights their potential for applications in fields such as soft robotics, and healthcare.

Abstract Perovskite solar cells (PSCs) offer high power conversion efficiency and low-cost fabrication, yet their use in wearable and consumer-facing technologies is limited by aesthetic constraints. This study introduces keratin-based coatings as skin-tone camouflage layers that preserve photovoltaic performance. Inspired by the stratum corneum, three formulations are developed: pure keratin (KER), keratin?melanin (KML), and keratin?KerMel (KKM), the latter incorporating synthetic melanin-mimetic particles. These coatings may serve as UV-protective top layers for PSCs. Characterization revealed that KKM exhibited nanoscale uniformity and enhanced durability, contributing to superior light management. KML showed the strongest UV-blocking capacity but reduced transparency, while KER offered high transparency with limited protection. Mechanical testing confirmed the robustness of all coatings, with tensile strengths of ≈3 MPa (KML), ≈2.5 MPa (KKM), and ≈1.7 MPa (KER). The KKM coating achieved a power conversion efficiency of ≈12%, compared to ≈15% in the uncoated reference, and outperformed both KER (≈10%) and KML (≈8%). Stability testing showed KKM retained ≈79% of its initial performance after 14 days, exceeding KER and KML, though slightly below the uncoated device. These results highlight keratin-based coatings as viable materials for merging functionality and aesthetics in renewable energy and biomedical applications.