Tématem této práce je počítačové modelování organického elektrochemického tranzistoru (OECT). Pro vytvoření modelu bylo třeba vypočítat rozložení elektrického pole a koncentrace iontů elektrolytu. Výpočet byl proveden numericky pomocí metody konečných prvků. Bylo vypočítáno rozložení elektrického potenciálu na povrchu kanálu OECT, dále byly vypočítány změny vodivosti a výstupní proud OECT. Výpočty byly provedeny na osobním počítači pomocí komerčního softwaru COMSOL Multiphysics. Kvůli nedostatečnému výpočetnímu výkonu musel být model rozdělen na části a drasticky zjednodušen. Prezentované výsledky se liší od literatury, protože se nepodařilo správně modelovat saturaci tranzistoru. Odchylky od reálného chování OECT jsou pravděpodobně způsobeny zjednodušením modelu.

The aim was to develop a sensing platform on the base of organic electrochemical transistor (OECT). The focus was on the preparation of proper electrode system and on optimalization of properties of thin layer of organic semiconductor. As a base, commercial glass substrates with integrated indium-tin oxide electrodes were chosen. Thin layers were prepared from organic semiconductor poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) by spin-coating. Four formulations of material were studied. Layers with different thickness were prepared and the dependence of transconductance on the thickness of the layer and ratio of width and length was observed. The degradation of electrode system was solved by galvanic plating with gold. Attention was also paid to modifications to PEDOT: PSS. It has been found that the optimal layer thickness for use in sensors is approximately 150 nm. By reducing the series resistance by using a silver paste, the transconductance of 23 mS was obtained for the Ink 2, for the Ink 3 the transconductance was 44 mS. Sensoric platforms with these transconductances can be used for detection of physiological functions of electrogenic cells, e.g. cardiomyocytes.

This thesis, written by Ingrid Öberg Månsson at KTH Royal Institute of Technology and entitled “Electroanalytical devices with fluidic control using textile materials and methods”, presents experimental studies on the development of textile based electronic devices and biosensors. One of the reasons why this is of interest is the growing demand for integrated smart products for wearable health monitoring or energy harvesting. To enable such products, new interdisciplinary fields arise combining traditional textile technology and electronics. Textile based devices have garnered much interest in recent years due to their innate ability to incorporate function directly into, for example, clothing or bandages by textile processes such as weaving, knitting or stitching. However, many modifications of yarns required for such applications are not available on an industrial scale. The major objective of this work has been to study how to achieve the performance necessary to create electronic textile devices by either coating yarns with conductive material or using commercially available conductive yarns that are functionalized to create sensing elements. Further, liquid transport within textile materials has been studied to be able to control the contact area between electrolyte and electrodes in electrochemical devices such as sensors and transistors. Yarns with specially designed cross-sections, traditionally used in sportswear to wick sweat away from the body and enhance evaporation, was used to transport electrolyte liquids to come in contact with yarn electrodes. The defined area of the junction where the fluidic yarn meets the conductive yarn was shown to increase stability of the measurements and the reproducibility between devices. The results presented in the two publications of this thesis as well as additional results presented in the thesis itself show the promising potential of using textile materials to integrate electronic and electrochemical functionality in our everyday life. This is shown by using basic textile materials and processing techniques to fabricate complex devices for various application areas such as sensors and diagnostics as well as electrical and energy harvesting components. / Denna avhandling, skriven av Ingrid Öberg Månsson vid Kungliga Tekniska Högskolan och titulerad ”Elektroanalytiska sensorer med vätskekontroll integrerad genom användande av textila material och metoder”, presenterar experimentella studier inom utvecklingen av textilbaserade elektroniska komponenter och biosensorer. Detta är av intresse på grund av den ökade efterfrågan på integrerade smarta produkter som till exempel bärbara sensorer för hälsoövervakning eller för att samla upp och konvertera energi till elektricitet. För att möjliggöra denna typ av produkter föds nya interdisciplinära fält där traditionell textilteknologi och elektronik möts. Textilbaserade enheter har väckt stort intresse under de senaste åren på grund av den naturliga förmågan att integrera funktion i till exempel kläder eller förband genom textila tillverkningsprocesser som väveri, stickning eller sömnad. Många modifikationer hos garner som krävs för att möjliggöra sådana tillämpningar är dock inte tillgängliga i större skala. Därför har det huvudsakliga syftet med denna studie varit att undersöka hur man kan uppnå den prestanda som krävs för att tillverka elektroniska textila komponenter, antingen genom att belägga garner med elektroniskt ledande material eller genom att använda kommersiellt tillgängliga ledande garner som sedan modifieras kemiskt för att skapa sensorer. Utöver detta har vätsketransport inom textila material studerats för att kunna styra och kontrollera kontaktytan mellan elektrolyt och elektroder i elektrokemiska enheter så som sensorer och transistorer. Garner med speciella tvärsnitt, som traditionellt använts i sportkläder för att transportera svett bort från kroppen och underlätta avdunstning, har använts för att transportera elektrolytvätska till elektroder av garn. Den definierade kontaktytan där det vätsketransporterade garnet korsar elektrodgarnet har visats öka stabiliteten av mätningen och reproducerbarheten mellan mätenheter. Resultaten som presenteras i de två artiklar som denna avhandling bygger på samt i avhandlingen själv visar på lovande potential för användandet av textila material för att integrera elektronisk och elektrokemisk funktionalitet i våra vardagsliv. Detta har uppnåtts genom att använda grundläggande textila material och tillverkningsprocesser för att tillverka komplexa enheter för olika tillämpningsområden så som sensorer för diagnostik samt elektroniska komponenter. / <p>QC 2020-08-21</p>

In recent years great advances in the field of biomedical engineering and organic electronics have been achieved. One promising application would be the regulation of blood glucose concentration in type 2 diabetes patients. This application would eliminate medication and would improve the standard of life. To achieve this goal a system is needed which receives information about the glucose concentration and reacts upon it. This output reaction could then be used to stimulate the body's own glucose regulation mechanisms. This thesis combined a glucose sensor with an artificial neuron to take the first step towards such a system. Two different artificial neurons, the Axon-Hillock neuron and the astable multivibrator, were characterized and examined upon their usability. The Axon-Hillock, build with organic electrochemical transistors, revealed that it could be applied for both regulating high and low blood glucose concentrations. The astable multivibrator, build with silicon-based transistors, was not as functional as the Axon-Hillock neuron but with more development it could become as good. The placement of the glucose sensor in the astable multivibrator circuit is essential parameter to consider. The results demonstrate that the examined system is functional and could become a part of a larger closed-loop system. Future tests on an animal model may demonstrate its viability as a treatment for type 2 diabetes.