skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.
Attention:The NSF Public Access Repository (NSF-PAR) system and access will be unavailable from 7:00 AM ET to 7:30 AM ET on Friday, April 24 due to maintenance. We apologize for the inconvenience.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • A recyclable PANI/PAAMPSA nanocomposite with repeatable, rapid, autonomous self-healing, and unprecedented electro-mechanical properties
Title: A recyclable PANI/PAAMPSA nanocomposite with repeatable, rapid, autonomous self-healing, and unprecedented electro-mechanical properties
Wearable sensors, stretchable electronics, and many soft robotic materials must have a balance of conductivity, stretchability, and robustness. Intrinsically conductive polymers offer a critical step toward improving wearable sensor materials due to their tunable conductivity, soft/compliant nature, and ability to complex with other coactive molecules (i.e., polyacids, small molecules). The addition of synergistic nanofillers has been shown to enhance the conductivity, self-healing, and mechanical properties of the polymers for soft robotics and wearable applications. The development of a robust polymer nanocomposite material that offers ultra-stretchability, an autonomous self-healing ability, and enhanced electronic properties has long eluded researchers. Herein, we show an aqueous polyaniline [PANI]:poly(2-acrylamido-2-methylpropane sulfonic acid) [PAAMPSA]:phytic acid [PA] polymer complex synthesized with 0.5 wt % silver nanowires (AgNW) to form a polymer nanocomposite with high electronic sensitivity, unique mechanical properties (a maximum strain of 4693%) and repeatable/autonomous self-healing efficiencies of greater than 98%. This AgNW polymer complex has an engineering strain higher than any reported hydrogel or other polymer-based sensor materials, in which the interface between the polymer matrix and the AgNW is hypothesized to be integral for the formation of the active electrically conductive network and unprecedented mechanical properties. To illustrate the remarkable sensitivity, the material was employed as a biomedical sensor (pulse, voice recognition, motion), topographical sensor, and high-sensitivity strain gauge.  more » « less
Award ID(s):
2305282 1942492
PAR ID:
10663329
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;
Publisher / Repository:
Springer Nature
Date Published:
Journal Name:
Advanced Composites and Hybrid Materials
Volume:
8
Issue:
5
ISSN:
2522-0128
Subject(s) / Keyword(s):
Repeatable self-healing Polymer electronics Ultra-stretchable Wearable sensors Extreme mechanical properties
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; (, Journal of Materials Chemistry A)
    null (Ed.)
    Development of highly stretchable and sensitive soft strain sensors is of great importance for broad applications in artificial intelligence, wearable devices, and soft robotics, but it proved to be a profound challenge to integrate the two seemingly opposite properties of high stretchability and sensitivity into a single material. Herein, we designed and synthesized a new fully polymeric conductive hydrogel with an interpenetrating polymer network (IPN) structure made of conductive PEDOT:PSS polymers and zwitterionic poly(HEAA- co -SBAA) polymers to achieve a combination of high mechanical, biocompatible, and sensing properties. The presence of hydrogen bonding, electrostatic interactions, and IPN structures enabled poly(HEAA- co -SBAA)/PEDOT:PSS hydrogels to achieve an ultra-high stretchability of 4000–5000%, a tensile strength of ∼0.5 MPa, a rapid mechanical recovery of 70–80% within 5 min, fast self-healing in 3 min, and a strong surface adhesion of ∼1700 J m −2 on different hard and soft substrates. Moreover, the integration of zwitterionic polySBAA and conductive PEDOT:PSS facilitated charge transfer via optimal conductive pathways. Due to the unique combination of superior stretchable, self-adhesive, and conductive properties, the hydrogels were further designed into strain sensors with high sensing stability and robustness for rapidly and accurately detecting subtle strain- and pressure-induced deformation and human motions. Moreover, an in-house mechanosensing platform provides a new tool to real-time explore the changes and relationship between network structures, tensile stress, and electronic resistance. This new fully polymeric hydrogel strain sensor, without any conductive fillers, holds great promise for broad human-machine interface applications. 
    more » « less
  2. ; ; ; ; ; (, Macromolecular Chemistry and Physics)
    Electrically conductive polymers are a groundbreaking class of materials commonly utilized in medical research focused on healthcare devices such as biosensors. They share the mechanical properties of a classical polymer as well as the electronic properties of metals. This allows them to function as flexible, lightweight, and highly efficient components in both wearable and implantable sensor technologies. Although research has shown promising findings, most of the polymer sensors presented are only partially or not at all biologically compatible with the human body. This work demonstrates a new electroconductive polymer matrix composed of bio‐based materials–bovine gelatin, whey protein isolate (WPI), polyaniline (PANI), and phytic acid (PA)– as a soft, compliant material. The results showed a homogeneous and well‐integrated matrix that remains stable up to . The water content in the samples ranged from 29.99% to 63.81%, depending on the method of preparation. The electromechanical properties before and after self‐healing were also investigated, along with antibacterial properties against both Gram‐positive (S. aureus) and Gram‐negative (E. coli) bacteria. This study developed a new formulation of a conductive polymer matrix that is potentially biocompatible, yet still exhibits satisfactory mechanical properties like its predecessors, making it a candidate for bio‐sensing applications. 
    more » « less
  3. ; ; ; ; ; (, Small Science)
    Stretchable conductive composites (SCCs) are generally elastomer matrices filled with conductive fillers. They combine the conductivity of metals and carbon materials with the flexibility of polymers, which are attractive properties for applications such as stretchable electronics, wearable devices, and flexible sensors. Most conventional conductive composites that are filled with only one type of conductive filler face issues in mechanical and electrical properties. Recently, some studies introduced secondary fillers to create hybrid‐filler SCCs to solve these problems. The secondary fillers produce a synergistic effect with the primary fillers to enhance the electrical conductivity of the composites. They also improve the thermal conductivity and mechanical properties or impart composites with special functions like catalysis and self‐healing. Herein, the fabrication methods, stretchability enhancement strategies, and piezoresistivity of SCCs are analyzed, and their latest applications in stretchable electronics are introduced. Finally, the challenges and prospects of their development are discussed. 
    more » « less
  4. ; ; ; ; (, ACS Applied Polymer Materials)
    Integration of multiple types of dynamic linkages into one polymer network is challenging and not well understood especially in the design and fabrication of dynamic polymer nanocomposites (DPNs). In this contribution, we present facile methods for synthesizing flexible, healable, conductive, and recyclable thermoresponsive DPNs using three dynamic chemistries playing distinct roles. Dynamic hydrogen bonds account for material flexibility and recycling character. Thiol-Michael exchange accounts for thermoresponsive properties. Diels–Alder reaction leads to covalent bonding between polymer matrix and nanocomposite. Overall, the presence of multiple types of orthogonal dynamic bonds provided a solution to the trade-off between enhanced mechanical performance and material elongation in DPNs. Efficient reinforcement was achieved using <1 wt % multiwalled carbon nanotubes as nanocomposite. Resulting DPNs showed excellent healability with over 3 MPa increase in stress compared to unreinforced materials. Due to multiple responsive dynamic linkages, >90% stress–relaxation was observed with self-healing achieved within 1 h of healing time. Increased mechanical strength, electrical conductivity, and reprocessability were achieved all while maintaining material flexibility and extensibility, hence highlighting the strong promise of these DPNs in the rapidly growing fields of flexible compliant electrodes and strain sensors. 
    more » « less
  5. ; ; ; ; ; ; ; (, Small Methods)
    Abstract The cost‐effective and scalable synthesis and patterning of soft nanomaterial composites with improved electrical conductivity and mechanical stretchability remains challenging in wearable devices. This work reports a scalable, low‐cost fabrication approach to directly create and pattern crumpled porous graphene/NiS2nanocomposites with high mechanical stretchability and electrical conductivity through laser irradiation combined with electrodeposition and a pre‐strain strategy. With modulated mechanical stretchability and electrical conductivity, the crumpled graphene/NiS2nanocomposite can be readily patterned into target geometries for application in a standalone stretchable sensing platform. By leveraging the electrical energy harvested from the kinetic motion from wearable triboelectric nanogenerator (TENG) and stored in micro‐supercapacitor arrays (MSCAs) to drive biophysical sensors, the system is demonstrated to monitor human motions, body temperature, and toxic gas in the exposed environment. The material selections, design strategies, and fabrication approaches from this study provide functional nanomaterial composites with tunable properties for future high‐performance bio‐integrated electronics. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email