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
  • Wearable high-dielectric-constant polymers with core–shell liquid metal inclusions for biomechanical energy harvesting and a self-powered user interface
Title: Wearable high-dielectric-constant polymers with core–shell liquid metal inclusions for biomechanical energy harvesting and a self-powered user interface
Deformable energy devices capable of efficiently scavenging ubiquitous mechanical signals enable the realization of self-powered wearable electronic systems for emerging human-integrated technologies. Triboelectric nanogenerators (TENGs) utilizing soft polymers with embedded additives and engineered dielectric properties emerge as ideal candidates for such applications. However, the use of solid filler materials in the state-of-the-art TENGs limits the devices' mechanical deformability and long-term durability. The current structural design for TENGs faces the dilemma where the enhanced dielectric constant of the TENG's contact layer leads to an undesirable saturation of the surface charge density. Here, we present a novel scheme to address the above issues, by exploring a liquid-metal-inclusion based TENG (LMI-TENG) where inherently deformable core–shell LMIs are incorporated into wearable high-dielectric-constant polymers. Through a holistic approach integrating theoretical and experimental efforts, we identified the parameter space for designing an LMI-TENG with co-optimized output and mechanical deformability. As a proof of concept, we demonstrated an LMI-TENG based wireless media control system for a self-powered user interface. The device architecture and design scheme presented here provide a promising solution towards the realization of self-powered human-integrated technologies.  more » « less
Award ID(s):
1726865
PAR ID:
10087819
Author(s) / Creator(s):
; ; ; ; ; ; ; ; ; ; ;
Date Published:
Journal Name:
Journal of Materials Chemistry A
ISSN:
2050-7488
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; (, Advanced Science)
    Abstract Stretchable triboelectric nanogenerators (TENGs) represent a new class of energy‐harvesting devices for powering wearable devices. However, most of them are associated with poor stretchability, low stability, and limited substrate material choices. This work presents the design and demonstration of highly stretchable and stable TENGs based on liquid metalel ectrodes with different phases. The conductive and fluidic properties of eutectic gallium‐indium (EGaIn) in the serpentine microfluidic channel ensure the robust performance of the EGaIn‐based TENG upon stretching over several hundred percent. The bi‐phasic EGaIn (bGaIn) from oxidation lowers surface tension and increases adhesion for printing on diverse substrates with high output performance parameters. The optimization of the electrode shapes in the bGaIn‐based TENGs can reduce the device footprint and weight, while enhancing stretchability. The applications of the EGaIn‐ and bGaIn‐based TENG include smart elastic bands for human movement monitoring and smart carpets with integrated data transmission/processing modules for headcount monitoring/control. Combining the concept of origami in the paper‐based bGaIn TENG can reduce the device footprint to improve output performance per unit area. The integration of bGaIn‐TENG on a self‐healing polymer substrate with corrosion resistance against acidic and alkaline solutions further facilitates its use in various challenging and extreme environments. 
    more » « less
  2. ; (, Advanced Composites and Hybrid Materials)
    Abstract The rapid advancement of self-powered wearable electronics has created an urgent demand for materials that can simultaneously enable efficient energy harvesting and reliable sensing while maintaining mechanical flexibility, breathability, and environmental robustness. Here, a carbon nanotube (CNT)-reinforced polytetrafluoroethylene (PTFE) nanofiber membrane with multiple functionalities is developed through an electrospinning-sintering strategy, integrating high breathability, super-hydrophobicity, and thermal resilience within a single architecture. The incorporation of CNTs enhances dielectric properties and mechanical strength, forming a robust charge-retentive fibrous network. The optimized membrane exhibits a super-hydrophobic surface with a water contact angle of 155.49°, along with excellent air permeability and outstanding thermal stability. When assembled into a triboelectric nanogenerator (TENG), the device delivers an open-circuit voltage of ~ 122 V, sufficient to power portable electronics. The TENG also demonstrates excellent fouling resistance and self-cleaning capability, maintaining stable performance after repeated contamination-washing cycles. Owing to its breathable and flexible configuration, the device enables real-time motion and respiration monitoring without compromising air exchange. It also exhibits consistent output under high-temperature (up to 250 °C) and underwater conditions, with the latter further showcased through Morse-code communication. This work establishes a scalable materials design strategy for multifunctional nanofibrous TENGs, offering a versatile platform for adaptive, self-powered electronic systems operable across diverse environments. 
    more » « less
  3. ; ; ; ; ; ; ; (, ACS applied materials interfaces)
    null (Ed.)
    Cellulose-based materials have gained increasing attention for the development of low cost, eco-friendly technologies, and more recently, as functional materials in triboelectric nanogenerators (TENGs). However, the low output performance of cellulose-based TENGs severely restricts their versatility and employment in emerging smart building and smart city applications. Here, we report a high output performance of a commercial cellulosic material-based energy harvesting floor (CEHF). Benefiting from the significant difference in the triboelectric properties between weighing and nitrocellulose papers, high surface roughness achieved by a newly developed mechanical exfoliation method, and large overall contact area via a multilayered device structure, the CEHF (25 cm × 15 cm × 1.2 cm) exhibits excellent output performance with a maximum output voltage, current, and power peak values of 360 V, 250 μA, and 5 mW, respectively. It can be directly installed or integrated with regular flooring products to effectively convert human body movements into electricity and shows good durability and stability. Moreover, a wireless transmission sensing system that can produce a 1:1 footstep-to-signal (transmitted and received) ratio is instantaneously powered by a TENG based entirely on cellulosic materials for the first time. This work provides a feasible and effective way to utilize commercial cellulosic materials to construct self-powered wireless transmission systems for real-time sensing applications. 
    more » « less
  4. ; ; ; ; ; ; ; ; ; (, Composites science and technology)
    null (Ed.)
    Self-healing triboelectric nanogenerators (SH-TENGs) with fast self-healing, high output performance, and wearing comfort have wide and promising applications in wearable electronic devices. This work presents a high-performance hydrogel-based SH-TENG, which consists of a high dielectric triboelectric layer (HDTL), a self-healing hydrogel electrode layer (SHEL), and a physical cross-linking layer (PCLL). Carbon nanotubes (CNTs), obtained by a chemical vapor deposition (CVD) method, were added into polydimethylsiloxane (PDMS) to produce the HDTL. Compared with pure PDMS, the short-circuit transferred charge (44 nC) and the open circuit voltage (132 V) are doubled for PDMS with 0.01 wt% CNTs. Glycerin, polydopamine particles (PDAP) and graphene were added to poly (vinyl alcohol) (PVA) to prepare the self-healing hydrogel electrode layer. SHEL can physically self-heal in ~1 min when exposed to air. The self-healing efficiency reaches up to 98%. The PCLL is made of poly(methylhydrosiloxane) (PMHS) and PDMS. It forms a good physical bond between the hydrophilic hydrogel and hydrophobic PDMS layers. The electric output performance of the SH-TENG can reach 94% of the undamaged one in 1 min. The SH-TENG (6 × 6 cm2) exhibits good stability and superior electrical performance, enabling it to power 37 LEDs simultaneously. 
    more » « less
  5. ; ; ; ; ; (, Droplet)
    Abstract Electrowetting‐on‐dielectric (EWOD) enables electrical modulation of liquid contact angle and is widely used for droplet actuation; however, its reliance on bulky high‐voltage power supplies limits portability. Triboelectric nanogenerators (TENGs) provide a lightweight, mechanically driven alternative, yet existing EWOD–TENG systems still rely on electronic controllers or rapid manual actions. Here, we present a hand‐powered and mechanically programmable EWOD platform that integrates a contact‐separation TENG (CS‐TENG) with a mechanically encoded punch‐card switch array, both driven by a single hand‐crank mechanism. Hand cranking simultaneously generates high voltage for EWOD actuation and advances a punch‐card tape to sequentially trigger electrode switching according to predefined punch‐hole patterns. Unlike conventional voltage sources, the CS‐TENG delivers a constant‐charge output per cycle, leading to distinct EWOD behavior. An EWOD–TENG model with trapped charge elucidates key phenomena, including bias‐dependent asymmetric EWOD arising from dielectric charge trapping and stepwise voltage attenuation caused by capacitive EWOD loading during sequential switching. The punch‐card switch array converts physical hole patterns into time‐synchronized electrode activation, enabling programmable droplet manipulation without electronic controllers. The resulting platform executes predefined droplet operations using only a hand crank as the sole energy and control input, achieving autonomous, portable, and robust droplet control for field‐deployable microfluidic systems. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Text Encoded Conversion
  • XML
  • Save / Share this Record
  • Send to Email