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[a] 1IntroductionInterest in real-timem onitoring of biochemical parameters using wearable/on-body sensors is ar apidly growing area of research [1],d ue in partt ot he convergence of interest of major economic sectors in applications based on new types of information. ICT companies like Apple and Googleare exploring ways to access biochemical information as am eans to move beyond the mature sensor technologies currently employed in exercise and sports APPs that track ausers location,body movements,temperature, energy expenditurea nd so on. These are typically based on physical transducers or imaging technologies embedded within wristbands or smart phones.H owever, employings imilar approaches that depend on time-series data to the domain of biochemical sensing is much more difficult, due to the complexc hallenges associated with access to representative samples (typically ab ody fluid) and the less predictable behavioro fc hemical sensors and biosensors over time.Since the exciting developments of the 1980s,t he application of biochemical sensing to real-timem onitoring of the human condition has scarcely advanced in terms of the performance of the sensors.T oday,t he use-model has almost entirely shifted awayf rom the early over-optimistic promise of implantable sensorst hat are in continuous contact with blood[ 2],t od evices sitedo utside the body that somehow can access ani nformation rich body fluid, like sweat [3] [4] or saliva [5].F or the past several decades,t he predominantu se model for health related diagnostics has been the disposable single-shot sensorc ombined with af inger prick access to blood samples.E xamples of use modelst hat involve real-time monitoring of body fluids (albeit over relatively short periods typically at most up to several days) include the integration of biosensors with contact lenses that can sample and report on the composition of ocular fluid,w hich is in turn reflective of the systemic blood composition [6].P erhapst he bestknown exampleo ft his is the collaborative ventureb etween Google and Novartis [7],b ased on Parviss work Abstract:Aplatform for harvesting and analysingt he sodium content of sweat in real time is presented. One is a watch format in which thes ampling and fluidic system,e lectrodes,c ircuitry and battery are arranged vertically,w hile in the other pod format, the electronics and battery components,a nd the fluidics electrodes are arranged horizontally.T he platformsa re designedt ob e securely attached to the skin using av elcros trap.S weat enters into the device through as ampling orifice and passes over solid-state sodium-selective and reference electrodes and into as torage area containing ah igh capacity adsorbent material. Thel iquid movement is entirely drivenb yc apillary action, and the flow rate through the device can be mediated through variation of the width of af luidic channel linking the electrodes to the sample storage area. Changing the width dimension through7 50, 500 and 250 mmp roduces flow rates of 38.20, 21.48 and 6.61 mL/min...

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

Wearable interfaces are central to multiple healthcare and wellness strategies encompassing diet and nutrition, personalized health monitoring, and performance optimization.

A feasibility study on a new technique capable of monitoring localized sweat rate is explored in this paper. Wearable devices commonly used in clinical practice for sweat sampling (i.e., Macroducts) were positioned on the body of an athlete whose sweat rate was then monitored during cycling sessions. The position at which the sweat fills the Macroduct was indicated by a contrasting marker and captured via a series of time-stamped photos or a video recording of the device during an exercise period. Given that the time of each captured image/frame is known (either through time stamp on photos or the constant frame rate of the video capture), it was, therefore, possible to estimate the sweat flow rate through a simple calibration model. The importance of gathering such valuable information is described, together with the results from a number of exercise trials to investigate the viability of this approach.

Abstract.In this paper, the preparation of a potentiometric strip for pH monitoring in saliva samples is reported. The potentiometric strip consists of a solid contact pH-selective and of a solidcontact ionogel reference electrode prepared on a dual screen printed substrate. The screen printing protocols, i.e., type of inks and number of deposits, were adjusted to relatively improve the batch reproducibility and the stability of the pH sensor. The pH of real saliva samples was monitored using the optimised potentiometric strip, and results were validated through parallel measurements with a standard laboratory method.

Solid-contact Pb 2+-selective-electrodes and solid contact reference electrodes suitable for use as disposable sensing devices for environmental monitoring of lead have been prepared on screen-printed substrates. Accurate control over the fabrication procedures leads to excellent reproducibility of their calibration characteristics such as slope, offset and limit of detection. In particular, the limit of detection in the nanomolar range opens the possibility of their use for trace analysis of Pb 2+ in environmental water samples. Significantly, the potentiometric measurements correlate well with data determined using inductively coupled plasma mass spectrometry (ICP-MS) in a number of real samples taken from local rivers. Ways in which these sensors might be employed in autonomous platforms for monitoring water quality in-situ are discussed. The possibility of including arrays of virtually identical sensors is highlighted as a possible route to achieve long-term deployments.