A5039763654- Smart Materials for Construction
- Advanced Sensor and Energy Harvesting Materials
- Analytical Chemistry and Sensors
- Structural Health Monitoring Techniques
- Electrical and Bioimpedance Tomography
- Non-Destructive Testing Techniques
- Infrastructure Maintenance and Monitoring
- Carbon Nanotubes in Composites
- Muscle activation and electromyography studies
- Concrete Corrosion and Durability
- Conducting polymers and applications
- Hydrology and Sediment Transport Processes
- Ultrasonics and Acoustic Wave Propagation
- Hydraulic flow and structures
- Micro and Nano Robotics
- Advanced Materials and Mechanics
- Advanced Fiber Optic Sensors
- Advanced Energy Technologies and Civil Engineering Innovations
- Sensor Technology and Measurement Systems
- Soft Robotics and Applications
- Mechanical Behavior of Composites
- Structural Engineering and Vibration Analysis
- Musculoskeletal pain and rehabilitation
- Polydiacetylene-based materials and applications
- Gas Sensing Nanomaterials and Sensors
University of California, San Diego
2015-2024
Royal Perth Hospital
2024
Institute of High Performance Computing
2022
Agency for Science, Technology and Research
2022
ORCID
2019
University of California, Davis
2009-2018
Dalian University of Technology
2018
University of California System
2009-2013
University of Michigan
2006-2008
Michigan United
2007
Typically, mechanical metamaterial properties are programmed and set when the architecture is designed constructed, do not change in response to shifting environmental conditions or application requirements. We present a new class of architected materials called field responsive metamaterials (FRMMs) that exhibit dynamic control on-the-fly tunability enabled by careful design selection both material composition architecture. To demonstrate FRMM concept, we print complex structures composed...
Since the discovery of carbon nanotubes, researchers have been fascinated by their mechanical and electrical properties, as well versatility for a wide array applications. In this study, nanotube–polyelectrolyte composite multilayer thin film fabricated layer-by-layer (LbL) method is proposed to develop multifunctional material measuring strain corrosion processes. LbL fabrication nanotube composites yields mechanically strong films in which multiple sensing transduction mechanisms can be...
As researchers continue to explore wireless sensors for use in structural monitoring systems, validation of field performance must be done using actual civil structures. In this study, a network low-cost was installed the Geumdang Bridge, Korea monitor bridge response truck loading. Such installations allow quantify accuracy and robustness systems within complex environment encountered field. total, 14 were concrete box girder span Bridge record acceleration responses forced vibrations...
In recent years, carbon nanotubes have been utilized for a variety of applications, including nanoelectronics and various types sensors. particular, researchers sought to take advantage the superior electrical properties fabricating novel strain This article presents single-walled nanotube (SWNT)-polyelectrolyte (PE) composite thin film sensor fabricated with layer-by-layer (LbL) process. Optimization bulk SWNT-PE is achieved by varying LbL fabrication parameters, followed characterization...
Machine vision-based structural health monitoring is gaining popularity due to the rich information one can extract from video and images. However, extraction of characteristic parameters images often requires manual intervention, thereby limiting its scalability effectiveness. In contrast, deep learning overcomes aforementioned shortcoming in that it autonomously feature (e.g. damage) image datasets. Therefore, this study aims validate use machine vision for by focusing on a particular...
The objective of this study was to design a multifunctional cement composite that could not only bear loads but also possessed electromechanical properties are sensitive damage. A mainstream approach is disperse large quantities conductive additives in the matrix, which can be costly, involve complex procedures, difficult scale-up, and degrade concrete’s inherent mechanical properties. Instead, research proposes new method self-sensing concrete, achieved by altering cement–aggregate...
Abstract Structural health monitoring (SHM) is the automation of condition assessment process an engineered system. When applied to geometrically large components or structures, such as those found in civil and aerospace infrastructure systems, a critical challenge designing sensing solution that could yield actionable information. This difficult task conduct cost-effectively, because surfaces under consideration localized nature typical defects damages. There have been significant research...
This paper describes the application of electrical impedance tomography (EIT) to demonstrate multifunctionality carbon nanocomposite thin films under various types environmental stimuli. Carbon nanotube (CNT) are fabricated by a layer-by-layer (LbL) technique and mounted with electrodes along their boundaries. The response stimuli is investigated relying on electric current excitation corresponding boundary potential measurements. spatial conductivity variations reconstructed based...
The need for structural health monitoring has become critical due to aging infrastructures, legacy airplanes, and continuous development of new technologies. Based on an updated design, there is a paradigms that can sense the presence, location, severity with single measurement. This paper focuses first step this paradigm, consisting applying sprayed conductive carbon nanotube-polymer film upon glass fiber-reinforced polymer composite substrates. Electrical impedance tomography performed...
Piezoelectric transducers are becoming increasingly popular for dynamic strain monitoring due to their small form factors and ability generate an electrical voltage drop in response strain. Although numerous types of piezoelectric thin films have been adopted sensing, it has shown that piezo-ceramics expensive, brittle, can fail during operation, while piezo-polymers possess lower piezoelectricity mechanical stiffness. Thus, the objective this study is develop a film characterized by high...
The objective of this letter is the fabrication and piezoelectric characterization poly(vinylidene fluoride)-trifluoroethylene (PVDF-TrFE) thin films enhanced with zinc oxide (ZnO) nanoparticles. incorporation ZnO nanoparticles will enhance bulk film piezoelectricity while preserving mechanical flexibility PVDF-TrFE. nanocomposites are fabricated by spin coating. Piezoelectric properties measured applying electric fields measuring their response using a Sawyer-Tower circuit.
Fiber-reinforced polymer (FRP) structures and components are highly susceptible to damage due delamination, matrix cracking, inter-laminar fracture, debonding, all of which have potential cause catastrophic structural failure. While numerous sensing technologies been developed embedded in FRP composites for monitoring strain, they serve as defects can promote formation propagation. Thus, this study, an alternative technique is proposed situ strain via layer-by-layer multi-walled carbon...
This work describes a novel method of embedded damage detection within glass fiber–reinforced polymer composites. Damage is achieved by monitoring the spatially distributed electrical conductivity strain-sensitive multiwalled carbon nanotube thin film. First, films were spray-deposited directly upon fiber mats. Second, using impedance tomography, spatial distribution film was determined before and after damage-inducing events. The resolution sensor drilling progressively larger holes in...
A target application of wearable sensors is to detect human motion and monitor physical activity for improving athletic performance delivering better therapy.In addition, measuring vital signals (e.g., respiration rate body temperature) provide rich information that can be used assess a subject's physiological or psychological condition.This study aims design multifunctional, wearable, fabric-based sensing system.First, carbon nanotube (CNT)-based thin films were first fabricated by...
This work provides a model for designing materials that humans perceive as soft based on material and geometric properties.
This study aims to validate the large-scale application of self-sensing concrete in airport runway pavements and use electrical resistance tomography (ERT) for characterizing spatially distributed damage during accelerated pavement testing. not only retains expected mechanical properties typical pavements, but it can also sense deformation strain. First, sensing were encoded by modifying cement-aggregate interface with multi-walled carbon nanotube (MWCNT) thin films. MWCNT films spray-coated...
Ultra-high-performance concretes (UHPCs) are characterized by extremely high packing densities. These densities can be achieved with optimization of grain size distribution incorporating a homogeneous gradient fine and coarse particles during mixing. Addition steel fibers increase the ductility under tensile loading tremendously. The density is key parameter for bond strength between UHPC matrix. objective this study twofold: to enhance behavior matrix increasing inclusion nanometer-sized...
Various types of strain sensors have been developed and widely used in the field for monitoring mechanical deformation structures. However, conventional are not suited measuring large strains associated with impact damage local crack propagation. In addition, resistive-type transducers, which mean that require an external electrical or power source. this study, a gold nanoparticle (GNP)-based polymer composite is proposed sensing. Fabrication composites relies on novel simple situ GNP...
This study investigated the design and performance of piezoelectric nanocomposite-based interdigitated transducers (IDTs) for active sensing damage detection. First, thin films that are highly mechanically flexible were designed by embedding zinc oxide (ZnO) nanoparticles in a poly(vinylidene fluoride–trifluoroethylene) (PVDF–TrFE) piezo-polymer matrix. Second, suspended nanoparticle solutions then spin coated onto patterned comb electrodes to fabricate IDTs. The poled align their electric...
Abstract Wearable sensors that measure parameters associated with physical activity and bodily motions have been regarded as an indispensable tool for assessing personal wellness. Recent advances in nanocomposite strain successfully used monitoring skin strains other strain‐derived physiological parameters. This study complements the existing body of work presents a flexible, self‐adhering, fabric‐based wearable sensor measuring human motions. Graphene nanosheet thin films are directly...
Low back pain (LBP) is a costly global health condition that affects individuals of all ages and genders. Physical therapy (PT) commonly used effective intervention for the management LBP incorporates movement assessment therapeutic exercise. A newly developed wearable, fabric-based sensor system, Motion Tape, uses novel sensing data modeling to measure lumbar spine movements unobtrusively thus offers potential benefits when in conjunction with PT. However, physical therapists' acceptance...
Cementitious composites such as concrete pavements are susceptible to different damage modes, which primarily caused by repeated loading and long-term deterioration. There is even greater concern that could worsen occur more frequently with the use of heavier vehicles or new aircraft carrying payloads. Thus, objective this research engineer cementitious capabilities self-sensing detecting damage. The approach was enhance sensitivity incorporating multi-walled carbon nanotubes (MWNT) part mix...