Textile-based Devices Research Articles

Design and fabrication of wearable electronic textiles using twisted fiber-based threads.

Mono-dimensional fiber-based electronics can effectively address the growing demand for improved wearable electronic devices because of their exceptional flexibility and stretchability. For practical applications, functional fiber electronic devices need to be integrated into more powerful and versatile systems to execute complex tasks that cannot be completed by single-fiber devices. Existing techniques, such as printing and sintering, reduce the flexibility and cause low connection strength of fiber-based electronic devices because of the high curvature of the fiber. Here, we outline a twisting fabrication process for fiber electrodes, which can be woven into functional threads and integrated within textiles. The design of the twisted thread structure for fiber devices ensures stable interfacing and good flexibility, while the textile structure features easily accessible, interlaced points for efficient circuit connections. Electronic textiles can be customized to act as displays, health monitors and power sources. We detail three main fabrication sections, including the fabrication of the fiber electrodes, their twisting into electronic threads and their assembly into functional textile-based devices. The procedures require ~10 d and are easily reproducible by researchers with expertise in fabricating energy and electronic devices.

The challenges of developing a textile-based device for recognizing swallowing movements during different swallowing tasks

Swallowing difficulty, also known as dysphagia, is a fairly common symptom that may lead to malnutrition, dehydration, pulmonary complications, and a reduced quality of life. Currently, a swallowing evaluation requires a hospital environment, skilled personnel, and expensive devices. Thus, it is important to develop a successful method for evaluating swallowing in an everyday environment. This study developed a textile-based solution that resembles a neck gaiter. Wireless accelerometer and gyroscope sensors embedded inside the gaiter were used to detect swallowing movements. The recognition of swallows was achieved through cervical auscultation and video footage, and this data was subsequently compared with the information obtained from wireless accelerometer and gyroscope sensors. Based on the measurement results for 17 adults without dysphagia, the developed neck gaiter can identify individual swallows of 5 sips of water (with a 97 % identification success rate) and consecutive swallows of 100 ml of water (98 % identification success rate). However, we were not able to recognize swallowing movements from speaking, chewing and head movements. Future research is now needed to develop a prototype to differentiate swallowing movements from other movements, such as chewing and speaking.

Interlocking-Governed Ultra-Strong and Highly Conductive MXene Fibers Through Fluidics-Assisted Thermal Drawing.

High-performance MXene fibers are always of significant interest for flexible textile-based devices. However, achieving high mechanical property and electrical conductivity remains challenging due to the uncontrolled loose microstructures of MXene (Ti3 C2 Tx and Ti3 CNTx ) nanosheets. Herein, high-performance MXene fibers directly obtained through fluidics-assisted thermal drawing are demonstrated. Tablet interlocks are formed at the interface layer between the outer cyclic olefin copolymer and inner MXene nanosheets due to the thermal drawing induced stresses, resulting in thousands of meters long macroscopic compact MXene fibers with ultra-high tensile strength, toughness, and outstanding electrical conductivity. Further, large-scale woven textiles constructed by these fibers offer exceptional electromagnetic interference shielding performance with excellent durability and stability. Such an effective and sustainable approach can be applied to produce functional fibers for applications in both daily life and aerospace.

Wearable Devices for Gait Measurement - A Case for Textile-Based Devices

Wearable devices for gait measurement are devices worn on the body to measure the gait of the wearers. During gait measurement, several parameters are measured and the choice of parameters is influenced by the application and by extension the gait index. Two approaches have been adopted in this research. One is the provision of an overview of wearable devices for gait measurement with a bias towards textile-based “soft” smart wearable systems using information from varied academic sources and databases. The second approach is to map out key scientific research trends within the wearable device classes using the Web of Science database. The focus is to make a case for textile-based gait measurement devices and systems while exploring the key determinants of wearable gait sensor placements and application efficiency. These soft smart wearable systems describe flexible material sensor-based systems which have their sensing mechanisms based on material deformation after being subjected to stress or pressure. This study could therefore serve as an apt reference for the development of soft smart wearable gait measurement systems as it throws light on the various soft wearable gait measurement applications, the bottlenecks in soft wearable device design, opportunities for developing new devices and the merit that soft gait analysis systems possess over their hard gait measurement counterparts.

Mechanofluidic Instability-Driven Wearable Textile Vibrotactor.

Vibration is a widely used mode of haptic communication, as vibrotactile cues provide salient haptic notifications to users and are easily integrated into wearable or handheld devices. Fluidic textile-based devices offer an appealing platform for the incorporation of vibrotactile haptic feedback, as they can be integrated into clothing and other conforming and compliant wearables. Fluidically driven vibrotactile feedback has primarily relied on valves to regulate actuating frequencies in wearable devices. The mechanical bandwidth of such valves limits the range of frequencies that can be achieved, particularly in attempting to reach the higher frequencies realized with electromechanical vibration actuators ( 100 Hz). In this paper, we introduce a soft vibrotactile wearable device constructed entirely of textiles and capable of rendering vibration frequencies between 183 and 233 Hz with amplitudes ranging from 23 to 114 g. We describe our methods of design and fabrication and the mechanism of vibration, which is realized by controlling inlet pressure and harnessing a mechanofluidic instability. Our design allows for controllable vibrotactile feedback that is comparable in frequency and greater in amplitude relative to state-of-the-art electromechanical actuators while offering the compliance and conformity of fully soft wearable devices.

Multifunctional wearable electronic textile based on fabric modified by MXene/Ag NWs for pressure sensing, EMI and personal thermal management

Flexible wearable electronics with multi-functions are bound to become the future development trend in the fields of intelligent device application, involving human healthcare, dynamic thermal management and even radiation protection. Herein, we promote a facile method that combines solution immersion and suspension spraying to assemble a poly(dimethylsiloxane)/Ag NWs/MXene/fabric (PAM@fabric) device. In particular, we use poly (diallyl dimethyl ammonium chloride) (PDAC) to pretreat the cotton fabric, which enables MXene to realize electrostatic self-assembly and greatly improve its stability. The multifunctional textile-based device with three-dimensional conductive network structure of MXene and Ag NWs presents durable and sensitive pressure sensing performance for detecting human joint motions and even subtle pulse. Besides, due to the excellent electrical conductivity of MXene and Ag NWs, the electronic also exhibits outstanding electromagnetic interference (EMI) shielding, as well as electrothermal conversion performance with controllability and extended cyclic stability. Accordingly, rational design provides a feasible path to prepare flexible multifunctional wearable devices.

Smart pH indicating functional fabric based on reversible acidichromic self-colored microparticles

Our study focuses on developing a novel wearable fabric with reversible acidichromic properties by dyeing it with self-colored hollow microparticles as polymeric dyes. To synthesize the pH-responsive chromophore, we introduced a self-synthesized 3-methyl-3-2,2′-dihydroxydiethylamine azobenzene (MDPD) to polyurethane microparticle shells. This prevented any dye leakage compared to conventional dye microcapsules. The self-colored microparticles exhibited an approximately spherical shape, with the particle size distribution ranging from 400 nm to 900 nm, peaking around 600 nm. By covalently bonding MDPD to the molecular chain of the polyurethane shell, we increased thermal stability and avoided dye leakage. We calculated the actual content of MDPD in the shell to be 3.84 %. To investigate the pH-responsive chromic mechanism of self-colored hollow microparticles, we characterized their color properties at various pH values. The polyester fabric dyed with pH-responsive self-colored microparticles showed a K/S value of up to 4.8. The dyed fabric exhibited a clear color change from yellow to rose red after decreasing the pH value, with a highly reversible mode, excellent color fastness, and aging resistance. Furthermore, we analyzed the combination mechanism of microparticles and polyester fabrics, highlighting the reversibility and large-area flexibility of pH-responsive microparticle dyed fabrics. The ability to accurately monitor pH levels in real-time using these fabrics opens new avenues for creating intelligent and responsive textile-based devices. As we continue our research and development, we aim to explore and maximize the potential of these fabrics, making them a valuable and innovative addition to the realm of wearable technologies.

Textile-based Wearable to Monitor Heart Activity in Paediatric Population: A Pilot Study.

Cardiac monitoring for children with heart disease still employs common clinical techniques that require visits to hospital either in an ambulatory or inpatient setting. Frequent cardiac monitoring, such as heart rate monitoring, can limit children's physical activity and quality of life. The main objective of this study is to evaluate the performance of a textile-based device (SKIIN) in measuring heart rate (HR) in different tasks: lying down, sitting, standing, exercising, and cooling down. Twenty participants including healthy children and children with heart disease were included in this study. The difference between the HRs recorded by the SKIIN was compared with a reference electrocardiogram collection by normalized root mean squared error. Participants completed a questionnaire on their experience wearing the textile device with additional parental feedback on the textile device collected. Participants had the median age of 14 years (range: 10-17 years), with body mass index 23.1 ± 3.8 kg/m2 and body surface area 1.70 ± 0.25 m2. The HR recorded by SKIIN and reference system significantly changes between tasks (P < 0.001), while not significantly different from each other (P > 0.05). The normalized root mean squared error was 3.8% ± 3.0% and 3.6% ± 3.7% for healthy and the heart disease groups, respectively. All participants found the textile device non-irritating and easy to wear. This study provides proof of concept that HR can be robustly and conveniently monitored by smart textiles, with similar accuracy to standard-of-care devices.

Emperor's new clothes: Novel textile-based supercapacitors using sheep wool fiber as electrode substrate

Textile-based supercapacitors (TSCs) are being used to meet the ever-increasing demand for mobile, safe, and convenient energy sources to power personal electronic devices. To that end, the smart textiles used in wearable technology need to be made from highly conductive yarns that are easily manufacturable. To date, synthetic- and cellulosic-based yarns have been exclusively used for the fabrication of TSCs, while other yarns have not been explored. Here, we used conductive protein-based yarns for TSCs and report on the use of wool coated with Ti3C2Tx MXene as a potential electrode material. To knit TSCs, wool and cotton yarns were coated with MXene flakes and their surfaces were characterized using Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS). The electrochemical characterization was conducted to examine the performance of wool- and cotton-based MXene electrodes as substrates and determine charge storage and resistive behavior. These tests showed that wool TSCs exhibited more pseudocapacitive behavior, while cotton TSCs exhibited a wider current range. At a scan rate of 5 mV/s, cotton TSCs presented an areal capacitance of 823.9 mF/cm2 while this value for the wool TSCs was 284 mF/cm2. The performance of yarns was also tested under various mechanical deformation conditions and after washing in order to assess the stability of TSCs. This study indicates the potential of protein-based yarns as electrode substrates for integration of MXene to fabricate smart textile-based devices.

All-Inkjet-Printed Ti3C2 MXene Capacitor for Textile Energy Storage

The emerging wearable electronics integrated into textiles are posing new challenges both in materials and micro-fabrication strategies to produce textile-based energy storage and power source micro-devices. In this regard, inkjet printing (IJP) offers unique features for rapid prototyping for various thin-film (2D) devices. However, all-inkjet-printed capacitors were very rarely reported in the literature. In this work, we formulated a stable Ti3C2 MXene aqueous ink for inkjet printing current-collector-free electrodes on TPU-coated cotton fabric, together with an innovative inkjet-printable and UV-curable solvent-based electrolyte precursor. The electrolyte was inkjet-printed on the electrode’s surface, and after UV polymerization, a thin and soft gel polymer electrolyte (GPE) was obtained, resulting in an all-inkjet-printed symmetrical capacitor (a-IJPSC). The highest ionic conductivity (0.60 mS/cm) was achieved with 10 wt.% of acrylamide content, and the capacitance retention was investigated both at rest (flat) and under bending conditions. The flat a-IJPSC textile-based device showed the areal capacitance of 0.89 mF/cm2 averaged on 2k cycles. Finally, an array of a-IJPSCs were demonstrated to be feasible as both a textile-based energy storage and micro-power source unit able to power a blue LED for several seconds.

Adhesive, multifunctional, and wearable electronics based on MXene-coated textile for personal heating systems, electromagnetic interference shielding, and pressure sensing.

Adhesion between flexible devices and skin surface facilitates portability of devices and reliable signal acquisition from human body, which is essential for medical therapy devices or monitoring systems. Here, we utilize a simple, cost-effective, and scalable layer-by-layer dip-coating method to fabricate a skin-adhesive multifunctional textile-based device, consisting of three parts: low-cost and easily available airlaid paper (AP) substrate, conductive MXene sensitive layer, and adhesive polydimethylsiloxane (PDMS). The adhesive layer of lightly cross-linked PDMS enables the device to form conformal contact with skin even during human joint bending. The smart textile device exhibits excellent electro-thermal and photo-thermal conversion performance with good cycling stability and tunability. Furthermore, the textile electronics show good electromagnetic interference (EMI) shielding properties due to the good electrical conductivity, as well as sensitive and stable pressure sensing properties for human motion detection. Consequently, this efficient strategy provides a possible way to design multifunctional and wearable electronic textiles for medical applications.

Carbon nanotubes boosts the toughness and conductivity of wet-spun MXene fibers for fiber-shaped super capacitors

Mechanically strong and electrically conducting fibers, particularly those with high specific capacitances, are promising fiber-shaped electrodes for fiber- and textile-based energy storage devices like fiber-shaped supercapacitors (FSCs). However, a high loading of fillers or bridging agents is commonly required to fabricate fiber electrodes with good mechanical strength, which compromises electrical conductivity and energy storage performance. Herein, an easily scalable wet-spinning strategy is reported to fabricate multifunctional Ti3C2Tx MXene/carbon nanotubes (MXene/CNT) hybrid fibers from a harmonious mixture of MXene and CNT in water and using acetic acid as a coagulation bath. The hybrid fiber achieved high strength (61 ± 7 MPa), good conductivity (1142.08 ± 40.04 S cm−1) and excellent energy storage performance (∼295 F g−1 at 5 mV s−1) at a very low CNT content of ∼1 wt%. When CNT loading increased to ∼9 wt%, the maximum strain at broken reached 161 ± 19 MPa and conductivity further increased to 1715 ± 22 S cm−1. The excellent mechanical performance allows hybrid fibers to be knitted into textiles for energy storage textiles. The assembled FSCs exhibit energy and power densities of ∼6.08 mW h cm−3 and ∼6440 mW cm−3, respectively. The excellent performance of MXene/CNT fiber and good feasibility for scalable production will open up new opportunities for the development of wearable and textile-based devices in the near future.

Ultra-compact MXene fibers by continuous and controllable synergy of interfacial interactions and thermal drawing-induced stresses

Recent advances in MXene (Ti3C2Tx) fibers, prepared from electrically conductive and mechanically strong MXene nanosheets, address the increasing demand of emerging yet promising electrode materials for the development of textile-based devices and beyond. However, to reveal the full potential of MXene fibers, reaching a balance between electrical conductivity and mechanical property is still the fundamental challenge, mainly due to the difficulties to further compact the loose MXene nanosheets. In this work, we demonstrate a continuous and controllable route to fabricate ultra-compact MXene fibers with an in-situ generated protective layer via the synergy of interfacial interactions and thermal drawing-induced stresses. The resulting ultra-compact MXene fibers with high orientation and low porosity exhibit not only excellent tensile strength and ultra-high toughness, but also high electrical conductivity. Then, we construct meter-scale MXene textiles using these ultra-compact fibers to achieve high-performance electromagnetic interference shielding and personal thermal management, accompanied by the high mechanical durability and stability even after multiple washing cycles. The demonstrated generic strategy can be applied to a broad range of nanostructured materials to construct functional fibers for large-scale applications in both space and daily lives.

Recognizing swallowing movements using a textile-based device

Dysphagia can stem from various etiologies and cause several serious complications. Instrumental evaluation methods for swallowing require special equipment not available everywhere. Thus, an instrumental means to evaluate swallowing that could be used outside a hospital setting would be critical. Dual-axis accelerometers have been utilized in earlier research to recognize swallowing movements. However, no textile-based approaches have been reported. In this study, we developed a textile-based prototype device for identifying swallowing movements. The device used accelerometers and gyroscopes, with eight sensors attached to the fabric. Two female participants were asked to perform two tasks while wearing the device around their neck: sitting still and taking 10 sips of water. The sensor attached to the middle of the thyroid notch level and the two sensors horizontally aligned to both sides of the hyoid bone level were the most accurate in recognizing swallowing movements. No sensor alone could recognize all swallows. However, all the swallows were identified using the combined data from the sensors. Thus, based on these preliminary results, it seems like a textile-based device using accelerometers and gyroscopes could identify swallowing movements.

Electroanalytical Paper-Based Nucleic Acid Amplification Biosensors with Integrated Thread Electrodes.

Nucleic acid amplification tests (NAATs) are very sensitive and specific methods, but they mainly rely on centralized laboratories and therefore are not suitable for point-of-care testing. Here, we present a 3D microfluidic paper-based electrochemical NAAT. These devices use off-the-shelf gold plasma-coated threads to integrate electroanalytical readouts using ex situ self-assembled monolayer formation on the threads prior to assembling into the paper device. They further include a sandwich hybridization assay with sample incubation, rinsing, and detection steps all integrated using movable stacks of filter papers to allow time-sequenced reactions. The devices use glass fiber substrates for storing recombinase polymerase amplification reagents and conducting the isothermal amplification. We used the paper-based device for the detection of the toxic microalgae Ostreopsis cf. ovata. The NAAT, completed in 95 min, attained a limit of detection of 0.06 pM target synthetic DNA and was able to detect 1 ng/μL O. cf. ovata genomic DNA with negligible cross-reactivity from a closely related microalgae species. We think that the integration of thread electrodes within paper-based devices paves the way for digital one-time use NAATs and numerous other advanced electroanalytical paper- or textile-based devices.

Development and Applications of MXene-Based Functional Fibers.

The increasing interest toward wearable and portable electronic devices calls for multifunctional materials and fibers/yarns capable of seamless integration with everyday textiles. To date, one particular gap inhibiting the development of such devices is the production of robust functional fibers with improved electronic conductivity and electrochemical energy storage capability. Recent efforts have been made to produce functional fibers with 2D carbides known as MXenes to address these demands. Ti3C2Tx MXene, in particular, is known for its metallic conductivity and high volumetric capacitance, and has shown promise for fibers and textile-based devices when used either as an additive, coating or the main fiber component. In this spotlight article, we highlight the recent exciting developments in our diverse efforts to fabricate MXene functionalized fibers, along with a critical evaluation of the challenges in processing, which directly affect macroscale material properties and the performance of the subsequent prototype devices. We also provide our assessment of observed and foreseen challenges of the current manufacturing methods and the opportunities arising from recent advances in the development of MXene fibers and paving future avenues for textile design and practical use in advanced applications.

Design framework for a seamless smart glove using a digital knitting system

The wearable electronics integrated with textile-based devices is a promising strategy to meet the requirements of human comfort as well as electrical performances. This research presents a design and development framework for a seamless glove sensor system using digital knitting fabrication. Based on the performance requirements of glove sensors for controlling a prosthetic hand, desirable design components include electrical conductivity, comfort, formfit, electrical sensitivity, and customizable design. These attributes are determined and achieved by applying appropriate materials and fabrication technologies. In this study, a digital knitting CAD/CAM system is utilized to meet the desired performance criteria, and two prototypes of the seamless glove sensor systems are successfully developed for the detection of both human and robotic finger motions. This digital knitting system will provide considerable potential for customized design development as well as a sustainable production process. This structured, systematic approach could be adapted in the future development of wearable electronic textile systems.

Highly Selective Metal-Organic Framework Textile Humidity Sensor.

The increase in demand and popularity of smart textiles brings new and innovative ideas to develop a diverse range of textile-based devices for our daily life applications. Smart textile-based sensors (TEX sensors) become attractive due to the potential to replace current solid-state sensor devices with flexible and wearable devices. We have developed a smart textile sensor for humidity detection using a metal–organic framework (MOF) as an active thin-film layer. We show for the first time the use of the Langmuir–Blodgett (LB) technique for the deposition of a MIL-96(Al) MOF thin film directly onto the fabrics containing interdigitated textile electrodes for the fabrication of a highly selective humidity sensor. The humidity sensors were made from two different types of textiles, namely, linen and cotton, with the linen-based sensor giving the best response due to better coverage of MOF. The TEX sensor showed a reproducible response after multiple cycles of measurements. After 3 weeks of storage, the sensor showed a moderate decrease in response. Moreover, TEX sensors showed a high level of selectivity for the detection of water vapors in the presence of several volatile organic compounds (VOCs). Interestingly, the selectivity is superior to some of the previously reported MOF-coated solid-state interdigitated electrode devices and textile sensors. The method herein described is generic and can be extended to other textiles and coating materials for the detection of toxic gases and vapors.

Highly Wearable, Breathable, and Washable Sensing Textile for Human Motion and Pulse Monitoring.

At present, pressure sensor textiles are of great significance in the area of wearable electronics, especially for making smart or intelligent textiles. However, the design of these textile-based devices with sensitive ability, simple fabrication, and low cost is still challenging. In this study, we developed a triboelectric sensing textile constructed with core-shell yarns. Nylon filament and polytetrafluoroethylene filament were selected as the positive and negative layers, respectively, in the woven structure while the built-in helical stainless steel yarn was serving as the inner electrode layer. The sensitivity of the sensing textile can reach up to 1.33 V·kPa-1 and 0.32 V·kPa-1 in the pressure range of 1.95-3.13 kPa and 3.20-4.61 kPa, respectively. This sensing textile presented good mechanical stability and sensing capability even after 4200 cycles of continuous operation or after 4 h continuous water washing. Benefiting from the favorable merits of being highly flexible, breathable, lightweight, and even dyeable, the fabricated device was capable of being placed on any desired body parts for quantifying the dynamic human motions. It can be effectively used to measure and monitor various human movements associated with different joints, such as the hand, elbow, knee, and underarm. Moreover, the sensing textile was able to capture real-time pulse signals and reflect the current health status for human beings. This study affords an innovative and promising track for multifunctional pressure sensor textiles with wide applications in smart textiles and personalized healthcare.

(Invited) Wearable Microfluidic and Electronic Frameworks for Biomedical Applications

I. Introduction Advances in wearable electronics, functional nanocomposite polymers, flexible microfluidics, and commercial polymer microfluidics are reported on a daily basis. However, much of this research is field-specific, despite the enormous potential that the convergence of these research areas has for the future of health care, worker safety, food safety, consumer devices, and commercial microfluidics. We present an innovative approach of powerful, general-purpose frameworks that facilitate interfacing of nanocomposite polymer-based, microfluidic, and electronic devices on flexible polymer, textile, or industrial polymer platforms. Such approaches offer practical solutions for areas such as safety lighting and health monitors for safety vests; heart monitors and perspiration monitors for athletic clothing; and other applications in real-time wearable bioelectric and biochemical monitoring. II. Wearable Microfluidic and Electronic Frameworks A. Wearable bioelectric sensors Intense research into wearable electronics has resulted in many innovative devices and systems, e.g.: flexible polyimide or Kapton printed circuit boards (PCBs) [1]; roll-to-roll foil and other printed devices [2]; printing and weaving of textiles [3]; and special geometries for flexible interconnect between rigid components [4]. We have investigated conductive nanocomposite polymers and metal transfer processes for wearable bioelectric sensors [5, 6]. These technologies can be employed in, for example, conformable and wearable systems for electrocardiogram (ECG) [5], tissue impedance [7] and pressure [8] sensors. Unlike many other techniques, the technology and materials employed for our devices are highly compatible with clothing-based textiles. B. Wearable microfluidics Much less research has been performed in the emerging area of wearable microfluidics. Traditionally, microfluidic devices are fabricated in rigid substrates or flexible materials such as polydimethylsiloxane (PDMS) that are bonded to rigid substrates. Free-standing PDMS devices are developed for, e.g., perspiration sensors [9]; however, such processes typically require long fabrication times, equipment in a cleanroom facility, and difficulty with integration onto textiles. Other devices employ porous materials or microneedles to deliver biofluids, e.g., perspiration or interstitial fluid, by capillary forces [10]; however, such devices are limited in fluid collection or are too invasive. Wearable textile-based devices have been recently demonstrated that use the textile itself as a fluidic “channel” [11]; however, such devices are dependent on the fluidic characteristics of the fabric. To overcome these limitations and facilitate the development of fully flexible, wearable, and durable microfluidic devices that can be used for a wider variety of applications, we have developed a printing-based fabrication process that employs screen printable plastisol ink [12]. This process is demonstrated for simple multi-level microfluidic devices toward the goal of fully wearable microfluidic systems. III. Summary Many methods have been developed for microelectronic and microfluidic devices in rigid or flexible packages (e.g., [13, 14, 15]). However, such technologies suffer from difficult integration and/or limited flexibility, limited geometries, limited microfluidic sample size, and/or difficult integration, especially on textile-based substrates. The technologies we present offer simple and compatible printing-based and transfer processes for microelectronic and microfluidic frameworks that facilitate cost-effective development of durable wearable biomedical systems. References Y. Chuo, et. al., IEEE Transactions Biomedical Circuits Systems 4(5):281-94 (2010).K. Jain, et. al., Proceedings of the IEEE 93(8):15000-10 (2005).F. Carpi, et. al., IEEE Transactions Information Technology Biomedicine 9(3):295-318 (2005).M. Gonzalez, et. al., Microelectronics Reliability 51:1069-76 (2011).D. Chung, et. al. Proc. SPIE 9060, (2014); doi:10.1117/12.2046548.D. Hilbich, et. al., Proc. SPIE 98020R (2016); doi:10.1117/12.2219284.D. Chung, et. al., J Electrochemical Society 161(2):B3071-76 (2014).A. Rahbar, et. al., Proc. SPIE 90600O (2014); doi:10.1117/12.2044342.J. Choi, et. al., Adv Healthcare Mater 6:1601355 (2017).F. Benito-Lopez, et. al., Procedia Chemistry 1(1):1103-1106 (2009).A. Nilghaz, et. al., Lab Chip 12:209-218 (2012).D. Chung & B.L. Gray, J Micromech Microeng, 27(11), (2017).S. Cheng., et. al., Advanced Functional Materials 21(12):2282-90 (2011).M. Scholles, et. al., Proc. of SPIE 7593:75930C-2 (2013).A. Wu, et. al., Lab Chip 10:519-521 (2010).