Personal Healthcare Applications Research Articles

A MOFs‐Derived Hydroxyl‐Functionalized Hybrid Nanoporous Carbon Incorporated Laser‐Scribed Graphene‐Based Multimodal Skin Patch for Perspiration Analysis and Electrocardiogram Monitoring

AbstractAlthough metal‐organic framework (MOF)‐derived nanoporous C (NPC) materials offer several advantages for electrochemical sensor applications, surface functionalization and porosity tuning can affect sensor performance. This study presents the development of a skin patch for perspiration and electrocardiogram (ECG) monitoring, leveraging the unique properties of MOF‐on‐MOF‐derived surface‐functionalized hybrid nanoporous C (f‐HNPC) incorporated into laser‐scribed graphene (LSG). Hydroxyl (OH) group‐functionalized NPC, achieved through KOH activation, facilitates electron transport at the electrode–electrolyte interface. This enhances the electrochemical activity, thereby improving sensor sensitivity and expanding the detection range. The integration of f‐HNPC provides enhanced surface area and electrochemical properties, enabling sensitive and selective detection of sweat biomarkers, including glucose (103 µA mM−1 cm−2) and uric acid (184 µA mM−1 cm−2) along with an ultra‐wide glucose detection range (up to 41.5 mM). Moreover, the incorporation of LSG ensures excellent mechanical flexibility, facilitating conformal contact with the skin for reliable signal acquisition. The proposed skin patch demonstrates promising performance in real‐time perspiration analysis and ECG monitoring with a signal‐to‐noise ratio of 23.63 dB, along with high stability and long‐term durability. The synergistic combination of f‐HNPC and LSG shows great potential for developing advanced wearable biosensing platforms for personalized healthcare applications.

Development of Highly Flexible Piezoelectric PVDF-TRFE/Reduced Graphene Oxide Doped Electrospun Nano-Fibers for Self-Powered Pressure Sensor.

The demand for self-powered, flexible, and wearable electronic devices has been increasing in recent years for physiological and biomedical applications in real-time detection due to their higher flexibility and stretchability. This work fabricated a highly sensitive, self-powered wearable microdevice with Poly-Vinylidene Fluoride-Tetra Fluoroethylene (PVDF-TrFE) nano-fibers using an electrospinning technique. The dielectric response of the polymer was improved by incorporating the reduced-graphene-oxide (rGO) multi-walled carbon nano-tubes (MWCNTs) through doping. The dielectric behavior and piezoelectric effect were improved through the stretching and orientation of polymeric chains. The outermost layer was attained by chemical vapor deposition (CVD) of conductive polymer poly (3,4-ethylenedioxythiophene) to enhance the electrical conductivity and sensitivity. The hetero-structured nano-composite comprises PVDF-TrFE doped with rGO-MWCNTs over poly (3,4-ethylenedioxythiophene) (PEDOT), forming continuous self-assembly. The piezoelectric pressure sensor is capable of detecting human physiological vital signs. The pressure sensor exhibits a high-pressure sensitivity of 19.09 kPa-1, over a sensing range of 1.0 Pa to 25 kPa, and excellent cycling stability of 10,000 cycles. The study reveals that the piezoelectric pressure sensor has superior sensing performance and is capable of monitoring human vital signs, including heartbeat and wrist pulse, masticatory movement, voice recognition, and eye blinking signals. The research work demonstrates that the device could potentially eliminate metallic sensors and be used for early disease diagnosis in biomedical and personal healthcare applications.

Smart Tattoo Sensors 2.0: A Ten-Year Progress Report through a Narrative Review.

The increased interest in sensing tattoos reflects a shift in wearable technology, emphasizing their flexible, skin-adherent nature. These devices, driven by advancements in nanotechnology and materials science, offer highly sensitive and customizable sensors. The growing body of research in this area indicates a rising curiosity in their design and applications, with potential uses ranging from vital sign monitoring to biomarker detection. Sensing tattoos present a promising avenue in wearable healthcare technology, attracting attention from researchers, clinicians, and technology enthusiasts. The objective of this study is to analyze the development, application, and integration of the sensing tattoos in the health domain. A review was conducted on PubMed and Scopus, applying a standard checklist and a qualification process. The outcome reported 37 studies. Sensing tattoos hold transformative potential in health monitoring and physiological sensing, driven by their focus on affordability, user-friendly design, and versatile sensorization solutions. Despite their promise, ongoing refinement is essential, addressing limitations in adhesion, signal quality, biocompatibility, and regulatory complexities. Identified opportunities, including non-invasive health monitoring, multiplexed detection, and cost-effective fabrication methods, open avenues for personalized healthcare applications. However, bridging gaps in medical device standards, cybersecurity, and regulatory compliance is imperative for seamless integration. A key theme calls for a holistic, user-centric approach, emphasizing interdisciplinary collaboration. Balancing innovation with practicality, prioritizing ethics, and fostering collaboration are crucial for the evolution of these technologies. The dynamic state of the field is evident, with active exploration of new frontiers. This overview also provides a roadmap, urging scholars, industry players, and regulators to collectively contribute to the responsible integration of sensing tattoos into daily life.

Conductive Peptide-Based MXene Hydrogel as a Piezoresistive Sensor.

Wearable pressure sensors have become increasingly popular for personal healthcare and motion detection applications due to recent advances in materials science and functional nanomaterials. In this study, a novel composite hydrogel is presented as a sensitive piezoresistive sensor that can be utilized for various biomedical applications, such as wearable skin patches and integrated artificial skin that can measure pulse and blood pressure, as well as monitor sound as a self-powered microphone. The hydrogel is composed of self-assembled short peptides containing aromatic, positively- or negatively charged amino acids combined with 2D Ti3C2Tz MXene nanosheets. This material is low-cost, facile, reliable, and scalable for large areas while maintaining high sensitivity, a wide detection range, durability, oxidation stability, and biocompatibility. The bioinspired nanostructure, strong mechanical stability, and ease of functionalization make the assembled peptide-based composite MXene-hydrogel a promising and widely applicable material for use in bio-related wearable electronics.

Portable smartphone-enabled dydrogesterone sensors based on biomimetic polymers for personalized gynecological care.

Dydrogesterone, a frequently prescribed synthetic hormone integral to the treatment of diverse gynecological conditions, necessitates precise quantification in complex human plasma. In this study, the development of a portable, smartphone-based electrochemical sensor employing screen-printed gold electrodes (SPAuEs) modified with a biomimetic, molecularly imprinted poly(methacrylic acid-co-methyl methacrylate) (MIP) is presented for dydrogesterone detection in human plasma. FTIR spectroscopy illustrates the transformation of a pre-polymer mixture into a polymerized matrix, while SEM reveals a uniform MIP/SPAuE surface morphology. The sensor fabrication protocol, encompassing MIP/SPAuE composition, polymerization solvent, incubation time, and scan rate, is optimized to achieve enhanced sensitivity. The MIP/SPAuEs sensor exhibits a linear sensor response to dydrogesterone within the concentration range of 1-500 nM, as evidenced by cyclic and differential pulse voltammetry. The MIP/SPAuE sensor demonstrates exceptional sensitivity, recording 8.2 × 10-3 μA nM-1, with a sub-nanomolar limit of detection (LOD = 370 pM), and low limit of quantification (LOQ = 1.12 nM), along with appreciable selectivity over common interferents. In real-world clinical applications, the designed sensor is effectively employed for the rapid and precise determination of dydrogesterone in human blood plasma, achieving a remarkable recovery of 81%. Furthermore, MIP/SPAuE coatings possess suitable stability over 15 days, indicating the robustness of the sensor material for multiple rounds of analysis. The developed sensor provides a sensitive, selective, and cost-effective solution for monitoring dydrogesterone in plasma during various gynecological disorders, allowing for personalized healthcare applications.

Piezoelectric nanogenerators for self-powered wearable and implantable bioelectronic devices.

One of the recent innovations in the field of personalized healthcare is the piezoelectric nanogenerators (PENGs) for various clinical applications, including self-powered sensors, drug delivery, tissue regeneration etc. Such innovations are perceived to potentially address some of the unmet clinical needs, e.g., limited life-span of implantable biomedical devices (e.g., pacemaker) and replacement related complications. To this end, the generation of green energy from biomechanical sources for wearable and implantable bioelectronic devices gained considerable attention in the scientific community. In this perspective, this article provides a comprehensive state-of-the-art review on the recent developments in the processing, applications and associated concerns of piezoelectric materials (synthetic/biological) for personalized healthcare applications. In particular, this review briefly discusses the concepts of piezoelectric energy harvesting, piezoelectric materials (ceramics, polymers, nature-inspired), and the various applications of piezoelectric nanogenerators, such as, self-powered sensors, self-powered pacemakers, deep brain stimulators etc. Important distinction has been made in terms of the potential clinical applications of PENGs, either as wearable or implantable bioelectronic devices. While discussing the potential applications as implantable devices, the biocompatibility of the several hybrid devices using large animal models is summarized. This review closes with the futuristic vision of integrating data science approaches in developmental pipeline of PENGs as well as clinical translation of the next generation PENGs. STATEMENT OF SIGNIFICANCE: Piezoelectric nanogenerators (PENGs) hold great promise for transforming personalized healthcare through self-powered sensors, drug delivery systems, and tissue regeneration. The limited battery life of implantable devices like pacemakers presents a significant challenge, leading to complications from repititive surgeries. To address such a critical issue, researchers are focusing on generating green energy from biomechanical sources to power wearable and implantable bioelectronic devices. This comprehensive review critically examines the latest advancements in synthetic and nature-inspired piezoelectric materials for PENGs in personalized healthcare. Moreover, it discusses the potential of piezoelectric materials and data science approaches to enhance the efficiency and reliability of personalized healthcare devices for clinical applications.

A new method of continuous blood pressure monitoring using multichannel sensing signals on the wrist

Hypertension is a worldwide health problem and a primary risk factor for cardiovascular disease. Continuous monitoring of blood pressure has important clinical value for the early diagnosis and prevention of cardiovascular disease. However, existing technologies for wearable continuous blood pressure monitoring are usually inaccurate, rely on subject-specific calibration and have poor generalization across individuals, which limit their practical applications. Here, we report a new blood pressure measurement method and develop an associated wearable device to implement continuous blood pressure monitoring for new subjects. The wearable device detects cardiac output and pulse waveform features through dual photoplethysmography (PPG) sensors worn on the palmar and dorsal sides of the wrist, incorporating custom-made interface sensors to detect the wearing contact pressure and skin temperature. The detected multichannel signals are fused using a machine-learning algorithm to estimate continuous blood pressure in real time. This dual PPG sensing method effectively eliminates the personal differences in PPG signals caused by different people and different wearing conditions. The proposed wearable device enables continuous blood pressure monitoring with good generalizability across individuals and demonstrates promising potential in personal health care applications.

A Mobile Two‐Dimensional Ultrasound Focusing System for Personalized Healthcare Applications through a Dodecagonal Quasicrystal Patterned Planar Lens (Adv. Mater. Technol. 16/2023)

A Mobile Two‐Dimensional Ultrasound Focusing System for Personalized Healthcare Applications through a Dodecagonal Quasicrystal Patterned Planar Lens (Adv. Mater. Technol. 16/2023)

A Mobile Two‐Dimensional Ultrasound Focusing System for Personalized Healthcare Applications through a Dodecagonal Quasicrystal Patterned Planar Lens

Ultrasound technology is widely utilized in applications, including tumor treatments, drug delivery, and skin care. However, improvements are required to prevent unwanted damage to non‐targeted tissues. The ultrasound focusing technology, represented by the highly intensive focused ultrasound (HIFU) technology, is actively researched to handle this problem. However, current technology is primarily limited in the point focusing of the ultrasound. Some applications, such as drug delivery and skin care, require 2D‐focusing of the ultrasound for effective utilization. Based on this necessity, this research proposes the rationally designed dodecagonal quasicrystal patterned (DQP) planar lens, which enables ultrasound focusing in 2D. The custom‐built ultrasound scanning setup confirms the 2D focusing behavior of the DQP lens. Furthermore, the developed DQP lens is integrated into the mobile ultrasound 2D focusing (MU2F) system and solved the bulkiness limitation of the HIFU system. The proposed MU2F system is applied in microneedle‐mediated drug delivery. The dramatic enhancement in the dissolution efficiency of the drug‐containing microneedle (≈2.5×) compared with the case without the MU2F system is confirmed. Through the proposed MU2F system, ultrasound‐based medical devices may widen their approachability from the clinic to the home.

A Computationally Assisted Approach for Designing Wearable Biosensors toward Non-Invasive Personalized Molecular Analysis.

Wearable sweat sensors have the potential to revolutionize precision medicine as they can non-invasively collect molecular information closely associated with an individual's health status. However, the majority of clinically relevant biomarkers cannot be continuously detected in situ using existing wearable approaches. Molecularly imprinted polymers (MIPs) are a promising candidate to address this challenge but haven't yet gained widespread use due to their complex design and optimization process yielding variable selectivity. Here, QuantumDock is introduced, an automated computational framework for universal MIP development toward wearable applications. QuantumDock utilizes density functional theory to probe molecular interactions between monomers and the target/interferent molecules to optimize selectivity, a fundamentally limiting factor for MIP development toward wearable sensing. A molecular docking approach is employed to explore a wide range of known and unknown monomers, and to identify the optimal monomer/cross-linker choice for subsequent MIP fabrication. Using an essential amino acid phenylalanine as the exemplar, experimental validation of QuantumDock is performed successfully using solution-synthesized MIP nanoparticles coupled with ultraviolet-visible spectroscopy. Moreover, a QuantumDock-optimized graphene-based wearable device is designed that can perform autonomous sweat induction, sampling, and sensing. For the first time, wearable non-invasive phenylalanine monitoring is demonstrated in human subjects toward personalized healthcare applications.

Fabrication of Eco-Friendly Wearable Strain Sensor Arrays via Facile Contact Printing for Healthcare Applications.

Wearable flexible strain sensors with spatial resolution enable the acquisition and analysis of complex actions for noninvasive personalized healthcare applications. To provide secure contact with skin and to avoid environmental pollution after usage, sensors with biocompatibility and biodegradability are highly desirable. Herein, wearable flexible strain sensors composed of crosslinked gold nanoparticle (GNP) thin films as the active conductive layer and transparent biodegradable polyurethane (PU) films as the flexible substrate are developed. The patterned GNP films (micrometer- to millimeter-scale square and rectangle geometry, alphabetic characters, and wave and array patterns) are transferred onto the biodegradable PU film via a facile, clean, rapid and high-precision contact printing method, without the need of a sacrificial polymer carrier or organic solvents. The GNP-PU strain sensor with low Young's modulus (≈17.8MPa) and high stretchability showed good stability and durability (10000 cycles) as well as degradability (42% weight loss after 17 days at 74°C in water). The GNP-PU strain sensor arrays with spatiotemporal strain resolution are applied as wearable eco-friendly electronics for monitoring subtle physiological signals (e.g., mapping of arterial lines and sensing pulse waveforms) and large-strain actions (e.g., finger bending).

Eco-friendly cellulose wearable heaters using Korean traditional Han paper coated with graphene nanosheets via binder-free supersonic spraying

Transparent and nontransparent exoskeleton wearable heaters are used in automobile and aircraft deicing, oil-pipeline defrosting, smart windows, underwater protection clothing, winter sportswear, bioelectronics, personal healthcare, athletic rehabilitation, and thermotherapy applications. In this study, we introduce Korean traditional Han paper (or Hanji), which comprises eco-friendly cellulose fibers from the mulberry bark, as a substrate for nontransparent wearable heaters. Hanji consists of cellulose fibers and is highly flexible, making it suitable for low-cost roll-to-roll scalable production. Graphene flakes are readily and firmly embedded inside the fibrous structure of Hanji by the catastrophic impact inflicted by supersonic spraying. Additionally, Hanji can withstand temperatures of up to 100 °C before suffering thermal damage. The heater with the thicker graphene layer had the lowest electrical resistance and exhibited the highest heating temperature at a constant voltage level. Graphene flakes are firmly held inside the fibrous structure of Hanji, securing the material's mechanical durability. Additionally, tests at various bending radii were conducted to demonstrate the mechanical strength of the Hanji graphene heater. Graphene flakes deposited on an unyielding alumina substrate withstood temperatures of up to 280 °C, thereby facilitating the use of the substrate in high-temperature applications. Graphene-coated textiles were heated and stretched up to 50%, thus demonstrating the application of such materials in human-body thermotherapy.

Highly sensitive and extremely durable wearable e-textiles of graphene/carbon nanotube hybrid for cardiorespiratory monitoring

Electroconductive textile yarns are of particular interest for their use as flexible and wearable sensors without compromising the properties and comfort of usual textiles. However, the detection of fine actions of the human body is quite challenging since it requires both the relatively higher sensitivity and stability of the sensor. Herein, highly sensitive, ultra-stable, and extremely durable piezoresistive wearable sensors were prepared by loading N-doped rGO and polydopamine-coated carbon nanotubes into silicon rubber tube. The wearable sensors thus produced show an excellent ability to sense subtle movement or stimuli with good sensitivity and repeatability. Furthermore, by bending the straight conductive silicon rubber tube (CSRT) into three different patterns, its sensitivity was then dramatically increased. Finally, the CSRT was found capable of sensing cardiorespiratory signals, indicating that the sensor would be an important step toward realizing bio-signal sensing for next-generation personalized health care applications.

Toward Sustainable Wearable Electronic Textiles.

Smart wearable electronic textiles (e-textiles) that can detect and differentiate multiple stimuli, while also collecting and storing the diverse array of data signals using highly innovative, multifunctional, and intelligent garments, are of great value for personalized healthcare applications. However, material performance and sustainability, complicated and difficult e-textile fabrication methods, and their limited end-of-life processability are major challenges to wide adoption of e-textiles. In this review, we explore the potential for sustainable materials, manufacturing techniques, and their end-of-the-life processes for developing eco-friendly e-textiles. In addition, we survey the current state-of-the-art for sustainable fibers and electronic materials (i.e., conductors, semiconductors, and dielectrics) to serve as different components in wearable e-textiles and then provide an overview of environmentally friendly digital manufacturing techniques for such textiles which involve less or no water utilization, combined with a reduction in both material waste and energy consumption. Furthermore, standardized parameters for evaluating the sustainability of e-textiles are established, such as life cycle analysis, biodegradability, and recyclability. Finally, we discuss the current development trends, as well as the future research directions for wearable e-textiles which include an integrated product design approach based on the use of eco-friendly materials, the development of sustainable manufacturing processes, and an effective end-of-the-life strategy to manufacture next generation smart and sustainable wearable e-textiles that can be either recycled to value-added products or decomposed in the landfill without any negative environmental impacts.

Highly Scalable, Sensitive and Ultraflexible Graphene‐Based Wearable E‐Textiles Sensor for Bio‐Signal Detection

AbstractGraphene‐based wearable electronic textiles (e‐textiles) show promise for next‐generation personalized healthcare applications due to their non‐invasive nature. However, the poor performance, less comfort, and higher material cost limit their wide applications. Here a simple and scalable production method of producing graphene‐based electro‐conductive yarn that is further embroidered to realize piezoresistive sensors is reported. The multilayer structures improved the conductivity of the piezoresistive sensors, exhibiting good sensitivity with high response and recovery speed. Additionally, the potential applications of such wearable, ultraflexible and machine‐washable piezoresistive sensors as pressure and breathing sensors are demonstrated. This will be an important step toward realizing multifunctional applications of wearable e‐textiles for next‐generation personalized healthcare applications.

Modeling Energy Aware Photoplethysmography for Personalized Healthcare Applications.

The rise of wearable health monitoring has largely incorporated photoplethysmography (PPG), an optical sensing modality, to determine heart rate and blood oxygen saturation metrics by reflecting light through a user's skin. Due to its optical nature, this sensing method is strongly impacted by the skin type, body mass index (BMI), and general physiological composition of the user. In the context of self-powering, there is a need for these devices to consume ultra-low power, to not be dependent on batteries and regular charging, enabling continuous monitoring. This paper presents a novel PPG sensing model for both a custom, ultra-low power (ULP) AFE and the Texas Instruments (TI) AFE4404 which is used to demonstrate the design tradeoffs between system power and SNR. The models also incorporate a novel human skin reflectance component to analyze the effect of the user's skin phototype and BMI on these tradeoffs with the goal of demonstrating inclusive, accurate ULP PPG sensing. Measured results on both devices from 23 participants are included to emphasize the limited design space for enabling self-powered, continuous monitoring wearables.

(Digital Presentation) Electrochemical Glutamate Sensor Using Copper Oxide Nanomaterials Functionalized with Multiwall Carbon Nanotubes

Glutamate is the most abundant neurotransmitter in the central nervous system (CNS) and plays an important role in different physiological processes. Excess amounts of glutamate cause excitotoxicity resulting in different diseases such as Alzheimer’s and glioma, pain disorders, spinal cord injuries, and cancer1-4. The concentration of glutamate in body fluids such as saliva is associated with those diseases. Therefore, glutamate is a potential biomarker for pathologies. By measuring glutamate levels in biofluids these pathologies can be monitored.Lab-based techniques such as liquid chromatography and gas chromatography offer a low limit of detection, high sensitivity, and precise detection of biomarkers4-7. These techniques are expensive, bulky, time-consuming, and require skilled personnel to operate them and therefore are not suitable for wearable and personalized healthcare applications. In contrast, electrochemical sensors are simple, low-cost, handy, and offer rapid and high sensing performance of biomarkers/analytes8,9.In this work, we fabricated a very simple, low-cost, and reusable enzyme-free electrochemical sensor using copper oxide (CuO) nanomaterials for label-free detection of glutamate. CuO nanomaterials were synthesized by a low-cost wet chemical process. The CuO nanomaterials were dispersed in DI water and the working electrode was prepared by drop casting of CuO dispersion on a screen-printed carbon electrode (SPCE). Multiwall carbon nanotubes (MWCNTs) were used with CuO to enhance the electron transfer from CuO to SPCE (Figure a). Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) were used to perform glutamate sensing in deionized (DI) water at pH 7.4. The peak oxidation current (I pa) is proportional to glutamate (G) presence in DI water (Figure b). The sensor showed good oxidation current event at a low concentration of glutamate (20 µM) in DI water. The normal concentrations of glutamate in body fluids such as plasma and saliva are about 5-100 µM, and 1-30 µM respectively 3. Therefore, CuO nanostructure-based nonenzymatic electrochemical sensor is very potential for low cost, portable, rapid detection of glutamate in those body fluids. We will further discuss details of CuO synthesis, electrode fabrication process, sensing mechanism, and challenges of the glutamate sensor.References Lewerenz and P. Maher, Frontiers in neuroscience. 9 (2015) 469.Takano et al., Nature medicine. 7 (2001) 1010-1015.H Jasim et al., Scientific reports 8.1 (2018): 1-9.Schultz, Z. Uddin, G. Singh, and M. M. Howlader, Analyst. 145 (2020) 321-347.Klimuntowski, M. M. Alam, G. Singh, and M. M. Howlader, ACS Sensor. 5(3) (2020) 620–636.Budczies et al., International journal of cancer. 136 (2015) 1619-1628.Xin et al, Chinese Journal of Analytical Chemistry. 35 (2007), 1151-1154.Hughes et al., Sensors and Actuators B: Chemical. 216 (2015) 614-621.Rocchitta et al., Sensors, 16 (2016) 780.X Zhang et al., The Journal of Physical Chemistry C 112.43 (2008): 16845-16849.Y Li et al., Materials Research Bulletin 43.8-9 (2008): 2380-2385.RP Allaker, and Z Yuan, Nanobiomaterials in clinical dentistry. Elsevier, 2019. 243-275. Figure 1

Fully printed and multifunctional graphene-based wearable e-textiles for personalized healthcare applications

SummaryWearable e-textiles have gained huge tractions due to their potential for non-invasive health monitoring. However, manufacturing of multifunctional wearable e-textiles remains challenging, due to poor performance, comfortability, scalability, and cost. Here, we report a fully printed, highly conductive, flexible, and machine-washable e-textiles platform that stores energy and monitor physiological conditions including bio-signals. The approach includes highly scalable printing of graphene-based inks on a rough and flexible textile substrate, followed by a fine encapsulation to produce highly conductive machine-washable e-textiles platform. The produced e-textiles are extremely flexible, conformal, and can detect activities of various body parts. The printed in-plane supercapacitor provides an aerial capacitance of ∼3.2 mFcm−2 (stability ∼10,000 cycles). We demonstrate such e-textiles to record brain activity (an electroencephalogram, EEG) and find comparable to conventional rigid electrodes. This could potentially lead to a multifunctional garment of graphene-based e-textiles that can act as flexible and wearable sensors powered by the energy stored in graphene-based textile supercapacitors.

Biocompatible composite thin-film wearable piezoelectric pressure sensor for monitoring of physiological and muscle motions

Whereas piezoelectric pressure sensors (PPSs) have been applied in the monitoring of human body movement and physiological parameters, they show inherent limitations in wearable applications, including toxicity, degradation, and brittleness. In this study, we develop safe, stable, and mechanically flexible composite thin films consisting of polyvinylidene fluoride (PVDF), BaTiO3 nanoparticles (BTO-NPs), and textured aluminum nitride (AlN) thin film for the demonstration of wearable PPS with enhanced output performance and biocompatibility. The PPS made of BTO-NP-embedded-PVDF and AlN film on Cu foil is attached to different parts of human body to measure different output voltages depending on the physiological and physical stimulus. The simple bending (from breathing, chewing, and swallowing), joint motions (at wrist, elbow, and finger), and low- (from eyeball movement) and high-pressure applications (by squat, lunge, and walking) are measured. Our PVDF+BTO-NP/AlN-PPS (PBA-PPS) device has the potential for personal safety, healthcare, and activity monitoring applications with easy wearability.

(Invited) Laser-Engraved Graphene-Based Wearable/mHealth Biosensors

Wearable sensors have the potential to provide rapid, non-invasive, and in-home health monitoring by real-time analyzing biomarkers in human sweat and saliva. However, most current biosensors suffer from low sensing accuracy for low-level analyte detection in biofluids and are difficult to fabricate on a large scale. In this talk, I will review our latest advances in developing fully-integrated laser-engraved graphene-based biosensors which can selectively and accurately measure a wide spectrum of sweat and saliva biomarkers including metabolites, nutrients, hormones, and proteins. The clinical value of these telemedicine platforms is evaluated through multiple human studies involving both healthy and patient populations toward metabolic monitoring and stress assessment. I will also introduce our recent work on a multiplexed wireless platform for the rapid COVID-19 test which could provide information on infection status, severity, and immunity. We envision that these telemedicine devices could open the door to a wide range of personalized healthcare applications.