Polymeric hydrogels are soft materials with a three-dimensional (3D) hydrophilic network capable of retaining and absorbing large amounts of water or biological fluids. Due to their customizable properties, these materials are extensively studied for developing matrices for 3D cell culture scaffolds, drug delivery systems, and tissue engineering. However, conventional hydrogels still exhibit many drawbacks; thus, significant efforts have been directed towards developing dynamic hydrogels that draw inspiration from organisms’ natural self-repair abilities after injury. The self-healing properties of these hydrogels are closely associated with their ability to form, break, and heal dynamic bonds in response to various stimuli. The primary objective of this review is to provide a comprehensive overview of dynamic hydrogels by examining the types of chemical bonds associated with them and the biopolymers utilized, and to elucidate the chemical nature of dynamic bonds that enable the modulation of hydrogels’ properties. While dynamic bonds ensure the self-healing behavior of hydrogels, they do not inherently confer adhesive properties. Therefore, we also highlight emerging approaches that enable dynamic hydrogels to acquire adhesive properties.

Healthcare has rapidly evolved in the last decades, driven by the demand for personalized therapies and advancements in enabling technologies. Among many solutions, fiber Bragg grating (FBG) sensors have gained significant acceptance in the medical field, due to their good static and dynamic performance, small dimensions, biocompatibility and immunity to electromagnetic interferences. The integration of artificial intelligence (AI) with FBGs is emerging as a breakthrough approach, enabling the design of smart systems for medical applications, like minimally invasive surgery, physiological monitoring, biomechanics, and medical biosensing. These systems harness the potential of FBGs and the advanced data processing capabilities of AI to improve diagnostics and therapeutic procedures. This perspective provides an overview of the sensing systems that combine FBG and AI technologies in medicine, focusing on their working principle, potentials, and challenges. It also explores the open research directions for encouraging further investigations in this field.

In a time of rapid global population growth, ensuring both food security and optimal crop yields is crucial. Effective monitoring of plant health is essential to address these challenges. Wearable sensing technology offers advantages over traditional methods, which often suffer from limitation in spatial and temporal resolution or susceptibility to environmental conditions. Recent advances have led to miniaturized sensors that can be affixed to plant organs. Fiber Bragg grating sensors (FBGs) embedded in flexible matrices are particularly suitable for plant wearables thanks to their lightweight, transparency and superior metrological properties. However, these flexible sensors need extra adhesive solutions, such as tapes or strings, to adhere to plants. This necessity could potentially impact plant physiology and compromise measurements accuracy. This study introduces an innovative plant wearable (PW) sensor that integrates an FBG sensor within a self-adhesive, transparent, hydrogel-based matrix composed of natural polymers (sodium alginate and xanthan gum). The adhesiveness and flexibility of the material, combined with FBG advantages, make it an ideal sensing solution for stable monitoring of plant growth by conformally adhering to plant surfaces without additional adhesives. This work details the hydrogel matrix preparation and characterization, the sensor design, fabrication, and metrological assessment of the sensor, that showed a linear response to strain (R ² >0.99; S _ε = 0.147 nm·mε ^-1 ). Finally, results of in vivo tests on plants demonstrated that the proposed sensor could autonomously adhere to plant surface without any adhesion loss and effectively monitor stem elongation without significantly affecting plant physiology.

Wearable sensors that combine high precision with conformability and skin adhesion are crucial for reliable and highly unobtrusive physiological monitoring. In this context, increasing efforts are directed toward next‐generation miniaturized self‐adhesive sensors employing different sensing technologies. Herein, for the first time a self‐adhesive sensor is developed for real‐time detection of physiological and biomechanical strain signals, by embedding a fiber Bragg grating (FBG) sensor into a soft, biomimetic, flexible matrix. This hydrogel‐based matrix, composed of gelatin methacrylate, xanthan gum, and glycerol, is engineered to balance fiber–matrix mechanical coupling and skin adhesion. The encapsulated FBG sensor exhibits stable optical response, reduced signal attenuation, and retains good sensitivity to both strain (0.07 nm mε ⁻¹ ) and temperature (0.01 nm °C ⁻¹ ). Preliminary on‐skin tests on a healthy volunteer demonstrate the ability to capture subtle physiological signals such as breathing and heartbeats, as well as limb motion. Notably, the self‐adhesive properties of the matrix enable firm skin contact without additional tapes, enhancing signal reliability, and reducing motion artifacts. This approach offers a robust, biocompatible, and scalable solution for wearable sensing, opening new opportunities in health monitoring, rehabilitation, and human–machine interfaces.

Wearable technologies enhance the accuracy of health monitoring, but ensuring at the same time user comfort remains a significant challenge. Flexible strain sensors have emerged as promising candidates for this task, thanks to their ability to conform to the body and capture subtle biomechanical signals. Among these, sensors based on fiber Bragg gratings (FBGs) offer advantages such as high sensitivity, flexibility, compactness, multiplexing capabilities, and immunity to electromagnetic interference. However, most FBG-based flexible sensors require external adhesives or fixations to maintain contact with the skin, which can limit comfort, usability, and reliability of collected data. This study introduces an innovative bilayer wearable (BW) sensor that integrates a single FBG within a stretchable silicone structure combined with a self-adhesive silicone layer. The device can be directly attached to the skin without any additional support, ensuring stable and comfortable wear even during motion. This work details the fabrication process and metrological characterization of the BW sensor exhibiting repeatable behavior under strain and low hysteresis across a wide range of traction speeds. Preliminary tests on healthy volunteers confirmed the sensor’s capability to be applied in biomedical scenarios ranging from vital signs monitoring to biomechanics. In particular, BW was able to accurately detect respiratory and heart rates, as well as joint movement and muscle contraction. The combination of soft adhesion and optical sensing performance makes the proposed BW sensor a promising tool for real-time, reliable health monitoring.

The growing demand for sustainable agriculture requires robust and innovative solutions for continuous plant health monitoring. The development of smart, minimally invasive, and highly adhesive sensing systems is crucial to provide reliable data for effective crop management. In this context, Fiber Bragg gratings (FBGs) prove to be a valid solution due to their high sensitivity, multiplexing capabilities, flexibility, lightness and transparency, making them ideal for long-term monitoring in outdoor conditions. This study presents a bidirectional wearable sensor based on FBG technology for fruit monitoring in an open-field scenario. The sensor, consisting of two orthogonally arranged FBGs embedded in a flower-shaped, transparent, biocompatible, self-adhesive hydrogel matrix, was fabricated through a two-step process. The influence of strain and environmental quantities (i.e., temperature and relative humidity) was investigated, yielding Så = 0.08 nm/må, S_T = 0.01 nm/°C, and negligible response to relative humidity. Finally, the sensor was applied to the surface of Solanum melongena (eggplant) over a five-day period. Despite fluctuating weather conditions, the sensor remained securely adhered throughout the entire monitoring duration and provided continuous real-time data, capturing periodic trends linked to the day–night cycle and revealing slight growth-related signal variations. This work demonstrates the potential of FBG-based sensors for long-term, multidirectional fruit monitoring, contributing to the advancement of precision agriculture tools for improved crop management and early detection of plant stress or disease.