We report a new easier method for the quantitative analysis of sodium in human sweat. To the best of our knowledge this is the first time this has been done successfully in a real-time manner. We consolidate sweat stimulation, collection and analysis functions into a single method. This temporal data opens up new possibilities in the study of human physiology, broadly applicable from assessing athletic performance and hydration levels to monitoring Cystic Fibrosis (CF) sufferers. Our compact Sodium Sensor Belt (SSB) consists of a sodium selective Ion Selective Electrode (ISE) integrated into a platform that can be interfaced with the human body during exercise. No skin cleaning regime or sweat storage technology is required as samples is continually wicked from skin to a sensing surface and on to a waste terminal via a fabric pump. After an initial equilibration period, a sodium plateau concentration was reached and monitored continuously. Atomic Absorption Spectroscopy (AAS) was used as a refe rence method, confirming accuracy. The plateau concentrations observed fell within expected literature ranges, further confirming accuracy. Daily calibration 2 repeatability (n=4) was ±3.0% RSD and over a three month period reproducibility was ±12.1% RSD (n=56). As a further application, we attempted to monitor the sweat of Cystic Fibrosis (CF) sufferers using the same device. We observed high sodium concentrations symptomatic of CF (~60mM Na + ) for 2 CF patients, with no conclusive results for the remaining patients due to their limited exercising capability. The real-time monitoring of hydration levels during physical exercise for health and performance purposes is a particularly promising application for the SSB at present.

A bstractThis work presents the fabrication, characterisation and the performance of a wearable, robust, flexible and disposable chemical barcode device based on a micro-fluidic platform that incorporates ionic liquid polymer gels (ionogels). The device has been applied to the monitoring of the pH of sweat in real time during an exercise period. The device is an ideal wearable sensor for measuring the pH of sweat since it does not contents any electronic part for fluidic handle or pH detection and because it can be directly incorporated into clothing, head-or wristbands, which are in continuous contact with the skin. In addition, due to the micro-fluidic structure, fresh sweat is continuously passing through the sensing area providing the capability to perform continuous real time analysis. The approach presented here ensures immediate feedback regarding sweat composition. Sweat analysis is attractive for monitoring purposes as it can provide physiological information directly relevant to the health and performance of the wearer without the need for an invasive sampling approach.

to produce a new generation of smart garments.Such affordable smart garments could fulfil diverse applications, ranging from work wear in specific industries to the almost infinite scenarios of personal use including energy harvesting/storage, force/pressure measurement, porosity or color variation, and sensors (movement, temperature, chemicals). [1][2][3][4][5][6][7] However, performance, scalability, and cost problems have restricted the deployment of currently available smart textiles. To build smart textiles on an industrial scale, method of manufacturing and material selection are two important requirements. The approach of new energy materials and novel fabrication methods are essential to develop wearable technologies. Wearable energy generating devices that can be seamlessly integrated into garments are a critical component of the wearable electronics genre. Currently flexible fiber energy harvesters have attracted significant attention due to their ability to be integrated into fabrics, or stitched into existing textiles. Large-scale production of energy harvester fibers using conventional manufacturing processes, however, is still a challenge.Energy harvesting from environmental mechanical sources such as body movements including finger imparting, [8] pushing, [9] stretching, [10] bending, [11] twisting, [12] air flow, [13] transportation movement, [14] and sound waves [15] has attracted widespread attention to promote flexible self-powered devices. [16] The best common mechanical energy harvesting methods are based on piezoelectric materials. [17] Piezoelectric materials can be classified in three categories: piezoelectric ceramics, piezoelectric polymers, and piezoelectric composites. [18] Unlike the energy harvesters utilizing solar or thermal energy, performance of piezoelectric generators is generally not limited by environmental factors. [19] Piezoelectric generators have received massive interest in energy harvesting technology due to their unique ability to capture the ambient vibrations to generate electric signals. [20] The unique energy transduction of piezoelectric materials enables their applications in fields of energy harvesting, actuators, [21] sensors, [22] structural health monitoring, and use in biomedical devices. [23] Numerous approaches have been used to fabricate piezoelectric generators, such as coating, [24] spinning, [25] depositing, [26] and printing. [27] Wearable energy harvesting is of practical interest for many years and for diverse applications, including development of self-powered wireless sensors within garments for human health monitoring. Herein, a novel approach is reported to create wearable energy generators and sensors using nanostructured hybrid piezoelectric fibers and exploiting the enormous variety of textile architectures. It is found that high performance hybrid piezofiber is obtained using a barium titanate (BT) nanoparticle and poly(vinylidene fluoride) (PVDF) with a mass ratio of 1:10. These fibers are knitted to form a wearable energy generator that pr...

A wearable device for real-time monitoring of sodium levels in sweat is presented.