Digital Theses Archive


Tesi etd-12142017-182520

Type of thesis
Organic bioelectronic platforms for electrical and chemical stimulation of biological systems
Scientific disciplinary sector
INGEGNERIA - Biorobotics
relatore Prof. DARIO, PAOLO
  • Cell stimulation
  • Conducting polymers
  • Nerve guidance conduits
  • Organic bioelectronics
  • Organic electronic ion pumps
  • Surface wrinkling
Exam session start date
The use of electrically-active polymers for sensing, recording, and stimulating biological systems is the focus of Organic Bioelectronics. Within the thesis, the development of three different organic platforms for stimulation of biosystems will be presented. Two of them use the conducting polymer poly(3,4-ethylene dioxythiophene) poly(styrene sulfonate) (PEDOT:PSS) as active material. In the first work, PEDOT:PSS wrinkled biointerfaces have been developed as multifunctional platforms for cell stimulation, combining electrical and topographic cues. An easy technique, which relies on heat-shrinking of pre-stressed polystyrene sheets, allowed for obtaining uniaxially micro-wrinkled PEDOT:PSS surfaces, which were used for guiding and electrically stimulating the axonal growth from neuronal cells. In the second work, the heat-shrink strategy has been exploited for fabricating multifunctional guidance tubes for peripheral nerve regeneration. PEDOT:PSS microelectrodes were patterned on polyolefin shrink-wrap films, which allowed for obtaining tubular guides with integrated organic electrodes for electrically stimulating the nerve regeneration. The heat-shrink strategy allowed for both miniaturizing the microelectrodes (while keeping the same actual surface area) and texturing the inner surface with guidance cues at the micro-scale. The third work, developed at the Laboratory of Organic Electronics of Linköping University (Sweden), is focused on the organic electronic ion pump (OEIP) technology. The OEIP platforms use ion-conducting polyelectrolytes as active organic materials, and provide a means for chemical stimulation of biological targets by electronically-regulated delivery of bioactive ionic compounds. Capillary fiber OEIPs have been developed with the aim to characterize the ionic transport properties of new polyelectrolyte materials based on dendritic polyglycerols. Given their highly branched structure and the large intermolecular spacing, such dendritic polyelectrolytes promise to outperform the polyelectrolytes traditionally used in OEIPs, thus opening the way toward the electronically-controlled delivery of a variety of large aromatic molecules.