Fish Scale Biomimetic Multifunctional Antifreeze Organogel for Flexible Strain Sensor Applications

Abstract

The applications of conductive hydrogels in the fabrication of wearable sensors have been highlighted in recent studies. However, water in traditional hydrogels is volatile at room temperature and readily frozen at subzero temperatures, resulting in material failure, which is critical in their practical applicability. In this paper, we prepared an organogel with sodium lignin sulfonate (Ls) and poly(vinyl alcohol) in a dimethyl sulfoxide and water dualsolvent system and embedded dense fish scale biomimetic clusters of silver nanospheres on the surface of the organogel to impart high electrical conductivity and mechanical and antimicrobial properties. The obtained organogel exhibited excellent mechanical strength (1.58 MPa stress and 680% tensile strain), freeze resistance (−90 °C), and antimicrobial activity (bacteriostatic rate of more than 98%). In addition, the electrical conductivity of the organic gel still reached a high value of 1.9 mS cm −1 at the ultralow temperature of −90 °C. Moreover, the organogel sensor exhibited high strain sensitivity and fast response to various human movements; therefore, it accurately monitored human movement signals and physiological signals. This study proposes a simple method to prepare multifunctional lignin-based antifreeze organogels for their application in complex flexible wearable electronic devices, opening prospects for lignin-based antifreeze organogels.

Comfortable, Anisotropic-Elastic, and Multilayered Fibrous Bandages with Enhanced Directional Tensile Performance

“…Recently, with the latest developments in training theory, the ideal bandage is considered to be a porous soft material with directional tensile performance along the length direction that provides fixation pressure to an injured body part without hindering the normal movements of other body parts, i.e., offers comfortable and anisotropic-elastic function . As such, the development of such bandages has emerged as a prominent subject in the field of wearable medical devices , and soft robotics . Traditional elastic bandages are mainly made of poorly breathable elastic membranes, which result in unfortunate comfort when worn for a long time.…”

Pressure-Responsive Self-Lubricating Ice-Phobic Organogel with High Mechanical Strength from Fluorinated Polynorbornene Networks

“…To date, researchers have found that materials with low modulus can effectively reduce the ice shear strength. − Gels are soft semisolid materials with excellent liquid storage capacity, giving them potential for use as anti-icing materials. − Golovin et al conducted a study to design and predict the ice adhesion strength of numerous ice-repellent polymers, ultimately identifying organogels as the most effective choice due to their exceptionally low ice adhesion . Subsequently, considering their softness, hydrophobicity, and low elastic modulus, polysiloxane (PDMS)-based organogels by immersing PDMS-based networks in lubricants (silicone oil, perfluoroalkylether, and liquid paraffin) were developed to obtain low/ultra low ice adhesion strength, while they generally showed poor durability because of the loss of liquid lubricant during usage …”