Title of work: Electrolyte Artist: Judit Fritz Konstfack, Ädellab   ABSTRACT How much of the ocean have I filtered while in tears? Many times, while growing up on an island have I laid eyes on the enormous surrounding body of water and wondered – is the sorrow still in there? In small portions the human body and the bodies of nature exposes each other as part of their own content. Offering a glimpse into a constant material flow. Diffusing the boundaries between object and subject. A material flow that makes it impossible to tell what anything really is, because it has already evolved. My tears taste like the ocean. So does my sweat. I Find comfort in knowing I constantly take part in something that is beyond my human comprehension. That I don’t need to fully understand why I am here, because it is obvious that I, and everyone else play a part. We just don’t know the whole scene. Though a post humanistic angle I have investigated the close relation between matter, material, the human body and the bodies of nature, to find a connection point which decreases the hierarchy between object and subject. By crystallizing matter derived from human body fluids and building a machinery that portrays the process I invite the perceiver to a closeup of their part in a never-ending system. The agency of this project is to raise questions rather than finding answers, as I believe the human is in need of reevaluating their way of thinking when it comes to material and resources. I have tried to shift focus from the human perspective and self-centeredness into a set where we participate rather than being the perceiver. Alchemy was used as both a method and as an art historical reference, as the alchemical mindset is to learn through the act of making. This has been blended with modern days technology and imagination to build a body of work that balances between science and art. While being heavily based on theory and research, the body of work is a translation in which I allowed myself to freely portray how I imagine the travelling of matter is systemized. I created a working place where studies of the unseen is concentrated and visualized. Where the many sorrows and the hard work of human beings crystallize into solids, becoming nature again. Or was it ever not? And vice versa. Throughout the project, even though separated from everything that I connect to being human, the crystals made from pure matter derived from sweat and tears could not be separated from the knowledge of their origin. Even as objects, I see them as subjects. A conclusion that shed light upon the relativeness between bodies. A conclusion that brings life into what is often seen as dead, simultaneously showing the complex machinery of an emotional being.

Background: Understanding lactate levels can provide important information aboutour body’s condition. For athletes, this can improve their training and prevent earlyfatigue. In healthcare, monitoring lactate can provide valuable information and potentially prevent life-threatening episodes. Lactate can be measured non-invasively byanalyzing sweat. This is advantageous over the typical blood sampling since it is saferand pain-free. Sweat can be stimulated by using a method called iontophoresis. Itapplies a small current between two electrodes placed on the skin’s surface, deliveringsubstances to the inner layer of the skin. Objectives: The aim of this study was to design a device that implements iontophoresis to activate sweat production and uses a microfluidic system to collect thesweat and deliver it to a lactate sensor and provide a signal. Methodology: A device was designed in AutoCAD and 3D printed. It was improvedby trial and error. A sweat collecting test was performed to validate the iontophoresissystem. The efficiency of the microfluidic system was tested by recording the time ittakes to collect enough sweat to get a lactate signal. Finally, calibration tests wereperformed to validate the lactate signal in the form of batch-mode and flow-mode. Results: The sweat collection test produced 27 µL of sweat in 15 minutes and 49 µLin 30 minutes. The microfluidic system delivered sweat to the sensor and activated itin less than 3 minutes. The linearity of the batch-mode calibration, R2-value, was0.9994, and for the flow-mode it was 0.8908.Conclusions: The iontophoresis system stimulated sweat production, which themicrofluidic system delivered to the lactate sensor successfully. The lactate sensorwas implemented into the device, and a signal was detected. However, it could not becalibrated efficiently enough to display the electric signal as a lactate concentration.

Lactate is an important biomarker in sports and the lactate threshold concept is one of the best indicators of endurance performance in an athlete. However, to quantify the lactate threshold, an invasive method to take a blood sample must be used. Limitations for this method include stopping the active exercise for blood sampling and no real-time feedback. Instead, a novel non-invasive wearable biosensor can be used to measure the lactate concentration in sweat. The sensor generates an electrical current depending on the lactate concentration in the sweat, and therefore must an electronic device called a potentiostat be used to condition the current. However, available potentiostats are not suitable for use in sports where form factor, battery life and wireless connectivity is important. This thesis aims to solve this by developing a wearable device and software which can be used to measure the lactate concentration in sweat in real-time during exercise. The development process consisted of the determination of specifications, prototype development and thorough laboratory and on-body testing. Finally, a novel wearable device and software capable of real-time lactate measurements in sweat during exercise were presented. The device, called LactateStat, was 58mm ∗ 55mm ∗ 13mm, the current consumption was only 7.8mA, the current measurement resolution was 0.5 nA, the limit of detection was 0.45 nA and the current measurement range was around 750 μA. LactateStat is one of the first of its kind and provides a base for future development as the hardware, firmware and software resources are provided as open-source. / Laktat är en viktig biomarkör inom idrott och konceptet laktattröskel är en av de bästa indikatorerna för uthållighet hos en idrottsutövare. Men för att mäta laktattröskeln krävs en invasiv metod som går ut på att man tar ett blodprov. Begränsningarna med denna metod är bland annat att idrottsutövningen måste stoppas för att ta ett blodprov och att man inte får realtidsåterkoppling. I stället kan en liten och icke-invasiv bärbar biosensor användas för att mäta laktatkoncentrationen i svett. Sensorn genererar en elektrisk ström beroende på laktatkoncentrationen i svetten och en enhet som kallas potentiostat måste därför användas för att mäta denna ström. Tillgängliga potentiostater är dock inte lämpliga för användning inom sport där formfaktor, batteritid och trådlös kommunikation är viktigt. Denna avhandling har som syfte att lösa detta genom att utveckla en bärbar enhet och mjukvara som kan användas för att mäta laktatkoncentrationen i svett i realtid under träning. Utvecklingsprocessen bestod av bestämning av specifikationer, framtagning av en prototyp och noggrann laboratorie- och kroppstestning. Som resultat presenterades en banbrytande bärbar enhet och mjukvara som kan mäta laktat i realtid i svett under träning. Enheten, som kallades LactateStat, var 58mm * 55mm * 13mm, den aktiva strömförbrukningen var 7.8mA, den bästa mätupplösningen för ström var 0.5 nA, detektionsgränsen var 0.45 nA och det maximala mätområdet för ström var ca. 750 μA. LactateStat är en av de första i sitt slag och ger en bas för framtida utvecklingsarbete eftersom hårdvaru-, programvaru- och mjukvaruresurserna tillhandahålls som öppen källkod.