Nanotehnologija srebra in uporaba srebrovih nanožičk v senzoriki

Nanotehnologija je v 21. stoletju pomembna industrijska panoga, usmerjena v razvoj novih naprav in materialov v nanometrskem merilu (1 nm = 10-9 m). V diplomskem delu sem proučila tematiko nano-srebra in srebrovih nanožičk. Nano-srebro je že od nekdaj znano po svojih protibakterijskih učinkih, srebrove nanožičke pa se zaradi izjemnih električnih in termičnih lastnosti uporabljajo v različnih aplikacijah v elektronskem svetu. V diplomskem delu sem opisala njihovo uporabo na področju senzorike, kjer se lahko uporabljajo v različnih vrstah senzorjev. Omejila sem se na mehanske senzorje in bolj podrobno preučila t. i. »uporovne lističe« (ang. strain gauge). Zanje se lahko določi faktor ojačitve G, ki podaja razmerje med relativnima spremembama upornosti in dolžine. Njegova vrednost za kovine je običajno okrog 2, za uporovne senzorje, ki vsebujejo srebrove nanodelce in srebrove nanožičke, pa je njegova vrednost precej večja, okoli 3766. Pomembna je še širina območja linearnega odziva senzorja, ki je za srebrove nanožičke, še dobra. Za razliko od njih, pa pri pogosto uporabljenih ogljikovih nanožičkah, temu ni tako. Srebrove nanožičke so zato primernejše za uporabo v kompozitnih materialih za senzorje (npr. polidimetilsiloksan nanokompozitPDMS).Nanotechnology is nowadays an important industrial field that strives to develop and produce new materials structured at the nanoscopic scale (1 nm = 10-9 m). In the present work we review the use of nano-silver and silver nanowires in connection to different sensors. Nano-silver has been known for its antibacterial properties, whereas silver nanowires possess exceptional electrical and thermal properties. Therefore, they are very interesting materials for various applications in sensorics and electronics. In this review we were interested in their use in the mechanical sensors, especially in strain gauges. The gauge factor, G, which defines the ratio between the relative change of the electrical resistance and the relative change in the length of the object, is an important property in this field. This value is approximately 2 for metals, while for the strain sensors made of silver nanoparticles and silver nanowires the value is much higher, around 3766. Another important factor is also the regime of the linear response of the sensor -silver nanowires have broad regime with rather constant value of gauge factor, which is not the case for the carbon nanowires, which are also commonly used. These characteristics make the silver nanowires well-suited for their use in composite materials for sensors (e.g., polydimethylsiloxane (PDMS) nanocomposite)