A personalized electronic textile for ultrasensitive pressure sensing enabled by biocompatible MXene/ PEDOT:PSS composite

Flexible,breathable,and highly sensitive pressure sensors have increasingly become a focal point of interest due to their pivotal role in healthcare monitoring,advanced electronic skin applications,and disease diagnosis.However,traditional methods,involving elastomer film-based substrates or encapsulation techniques,often fall short due to mechanical mismatches,discomfort,lack of breathability,and limitations in sensing abilities.Consequently,there is a pressing need,yet it remains a significant challenge to create pressure sensors that are not only highly breathable,flexible,and comfortable but also sensitive,durable,and biocompatible.Herein,we present a biocompatible and breathable fabric-based pressure sensor,using nonwoven fabrics as both the sensing electrode(coated with MXene/poly(3,4-ethylenedioxythiophene):polystyrene sulfonate[PEDOT:PSS])and the interdigitated electrode(printed with MXene pattern)via a scalable spray-coating and screen-coating technique.The resultant device exhibits commendable air permeability,biocompatibility,and pressure sensing performance,including a remarkable sensitivity(754.5 kPa^(−1)),rapid response/recovery time(180/110 ms),and robust cycling stability.Furthermore,the integration of PEDOT:PSS plays a crucial role in protecting the MXene nanosheets from oxidation,significantly enhancing the device's long-term durability.These outstanding features make this sensor highly suitable for applications in fullrange human activities detection and disease diagnosis.Our study underscores the promising future of flexible pressure sensors in the realm of intelligent wearable electronics,setting a new benchmark for the industry.

Ultrathin and Flexible CNTs/MXene/Cellulose Nanofibrils Composite Paper for Electromagnetic Interference Shielding

As the rapid development of portable and wearable devices,different electromagnetic interference(EMI)shielding materials with high efficiency have been desired to eliminate the resulting radiation pollution.However,limited EMI shielding materials are successfully used in practical applications,due to the heavy thickness and absence of sufficient strength or flexibility.Herein,an ultrathin and flexible carbon nanotubes/MXene/cellulose nanofibrils composite paper with gradient and sandwich structure is constructed for EMI shielding application via a facile alternating vacuum-assisted filtration process.The composite paper exhibits outstanding mechanical properties with a tensile strength of 97.9±5.0 MPa and a fracture strain of 4.6±0.2%.Particularly,the paper shows a high electrical conductivity of 2506.6 S m?1 and EMI shielding effectiveness(EMI SE)of 38.4 dB due to the sandwich structure in improving EMI SE,and the gradient structure on regulating the contributions from reflection and absorption.This strategy is of great significance in fabricating ultrathin and flexible composite paper for highly efficient EMI shielding performance and in broadening the practical applications of MXene-based composite materials.

Bioinspired MXene-Based User-Interactive Electronic Skin for Digital and Visual Dual-Channel Sensing

User-interactive electronic skin(e-skin) that could convert mechanical stimuli into distinguishable outputs displays tremendous potential for wearable devices and health care applications. However, the existing devices have the disadvantages such as complex integration procedure and lack of the intuitive signal display function. Here, we present a bioinspired user-interactive e-skin, which is simple in structure and can synchronously achieve digital electrical response and optical visualization upon external mechanical stimulus. The e-skin comprises a conductive layer with a carbon nanotubes/cellulose nanofibers/MXene nanohybrid network featuring remarkable electromechanical behaviors, and a stretchable elastomer layer, which is composed of silicone rubber and thermochromic pigments. Furthermore, the conductive nanohybrid network with outstanding Joule heating performance can generate controllable thermal energy under voltage input and then achieve the dynamic coloration of silicone-based elastomer. Especially, such an innovative fusion strategy of digital data and visual images enables the e-skin to monitor human activities with evermore intuition and accuracy. The simple design philosophy and reliable operation of the demonstrated e-skin are expected to provide an ideal platform for next-generation flexible electronics.

Assembly of Nanowires into Macroscopic One‑Dimensional Fibers in Liquid State

Natural structural materials,such as spider silk,wood,and bone,are universally acknowledged as the gold standard for the ideal combinations of strength and toughness.The exceptional integrated performance of these biological materials can be ascribed to their multiscale hierarchical architectures and components.Mimicking the hierarchical assembly feature of natural materials,artificial fibers,which are generated through the one-dimensional(1D)assembly of nanowires,have been widely reported with remarkable flexibility and functionality.Furthermore,the distinguishing feature of nanowires’1D assembly can bridge the unique properties of nanowires with their potential functional applications.This tutorial review summarizes the recent developments in the assembly of nanowires into macroscopic 1D fibers in the liquid state.We begin by introducing the general strategies and mechanisms for assembling nanowires in one direction and then,illustrate their potential applications in energy storage,sensors,biomedical engineering,etc.Finally,a brief summary and some personal perspectives on the future research directions of nanowires’1D assembly are also proposed.

Very weak solutions to the two-dimensional Monge-Ampére equation Dedicated to Professor Jean-Yves Chemin on the Occasion of His 60th Birthday

In this short note we revisit the convex integration approach to constructing very weak solutions to the 2D Monge-Ampére equation with H?lder-continuous ?rst derivatives of exponent β < 1/5. Our approach is based on combining the approach of Lewicka and Pakzad(2017) with a new diagonalization procedure which avoids the use of conformal coordinates, which was introduced by De Lellis et al.(2018) for the isometric immersion problem.