All-Organic Electrochromic Spandex

Fiber-based opto-electronic components such as light-emitting diodes (LEDs), [ 1 , 2 ] solar cells, [3][4][5] electrochromic pixels [ 6 ] and transistors [7][8][9][10][11][12] attract increasing attention for their alternative, nonplanar device architectures, which readily permit integration into 'smart' fabrics. Furthermore, devices such as transistors facilitate advanced patterning schemes of electronic circuitry through judicious weaving. [9][10][11][12] In particular conjugated polymers are suited as the (semi)conductor since they either inherently possess the required mechanical toughness or can be processed together with suitable structural polymers-including both, natural and synthetic macromolecules [ 13 , 14 ] -and thus permit the manufacture of fl exible artifacts such as tapes and fi bers. Without doubt, one of the most alluring textile materials is silk from the silkworm Bombyx mori with its delicate texture and brilliant luster. Besides, once thoroughly degummed Bombyx mori silk offers a high degree of biocompatibility, [ 15 ] which is an indispensable characteristic in particular for electronic devices that are intended to operate in a biological environment. As a result, the design of optical, [ 16 , 17 ] electrical [ 18 , 19 ] and electronic [ 20 ] components on silk-based templates has been the subject of much recent research. However, all examples have -so far-been limited to devices that comprised inorganic metal/semiconductor thin-fi lm structures on 'silk fi lms' that were produced from dissolved silk proteins. Clearly, although attractive due to their biodegradability (cf. Ref. 19 and 20) such architectures fail to benefi t from the extraordinary mechanical properties of pristine silk fi bers [ 21 , 22 ] and cannot be woven into fabrics. In a previous report, we have demonstrated that conjugated polyelectrolytescompounds that are uniquely suited to functionalize polypeptide structures [23][24][25][26] -permit facile staining of recombinant spider silk as well as natural Bombyx mori silk. [ 13 ] Depending on the choice of conjugated polyelectrolyte this approach enabled us to produce electrically conductive or photoluminescent fi bers. Here, we explore by which means such conducting silk fi bers can be incorporated as the structural as well as active component into electrochemical transistors (ECTs) that employ an electrolyte mixture composed of imidazolium-based ionic liquids as the electrochemical medium. ECTs offer unique possibilities for the realization of fi ber-based electronic circuits because of their relative insensitivity to the precise device geometry. [ 11 ] Ultimately, we anticipate that such components will permit fully integrated woven logic based on silk fi bers.We elected to work with silk fi bers from the silkworm Bombyx mori because of their availability and widespread use in textile manufacturing. Discrete degummed silk fi bers and threads thereof were obtained from Aurora Silk (Portland, Oregon, USA) and were used as received. As the conjugated polyelectrolyte we c...

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confidence: 99%

Woven Electrochemical Transistors on Silk Fibers

et al. 2010

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“…PEDOT:PSS has been spun into microfibers [35], and has been coated onto Spandex fabric to act as a back contact for an electrochromic display (σ=0.5 S/cm) [36]. The latter work was later expanded to include several other fabric combinations [37].…”

Section: Discussionmentioning

confidence: 99%

Conductive polymer-coated threads as electrical interconnects in e-textiles

et al. 2011

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An organic polymer electrical interconnect is demonstrated. The ionomer mixture poly(3,4-ethylenedioxythiophene): poly(styrenesulfonate) (PEDOT:PSS; 1:2.5, w:w) was cast onto silk fibers from a 50:50 (v:v) ethylene glycol solution by a dip-coating process. Dynamic mechanical analysis (DMA) results show that Young's modulus and mechanical strength are maintained during the coating process from acidic solution (pH ~1). DMA dynamic temperature scans reveal two new thermal transitions once PEDOT:PSS is applied to the silk fiber, and they are assigned to the glass transition temperature (59 o C) and melting point (146 o C) of the ionomer pair. Electrical conductivities of 8.5 S/cm were achieved with four cycles of the dip-coating process, only 10x less than Ag-coated thread control samples. SEM imaging of the PEDOT:PSS-coated fibers show slight texturing to the fibers due to the coating, as well as significant charging in the uncoated samples when compared to PEDOT:PSS-coated samples. The conductive fibers fabricated by this process were successfully applied as electrical interconnects in flexible, fully functional 555 timer circuits stitched into fabric substrates.

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“…Until now, several types of polythiophenes partially containing EDOT have been synthesized and successfully applied to electrochromic devices because of the stable nature of the oxidized state [18]- [24]. However, there are few reports on the characterization of these polymers and their charge transport properties.…”

Section: Introductionmentioning

confidence: 99%

Synthesis of Soluble Polythiophene Partially Containing 3,4-Ethylenedioxythiophene and 3-Hexylthiophene by Polycondensation

Imae¹,

Sagawa²,

Mashima³

et al. 2014

OJPChem

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A novel poly(quinquethiophene) partially containing 3,4-ethylenedioxythiophene (EDOT) and 3-hexylthiophene, poly(3,3''''-dihexyl-3',4',3''',4'''-diethylenedioxy-2,2':5',2'':5'',2''':5''',2''''-quinquethiophene), was synthesized by three types of polycondensations. Among them, direct C-H coupling reaction gave the polymer with the highest molecular weight. The resulting polymer was soluble in common organic solvents. Absorption and fluorescence spectra of the polymer showed a remarkable red-shift compared with the corresponding monomer due to the expansion of effective π-conjugation length.

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All-Organic Electrochromic Spandex

Cited by 127 publications

References 41 publications

Woven Electrochemical Transistors on Silk Fibers

Woven Electrochemical Transistors on Silk Fibers

Conductive polymer-coated threads as electrical interconnects in e-textiles

Synthesis of Soluble Polythiophene Partially Containing 3,4-Ethylenedioxythiophene and 3-Hexylthiophene by Polycondensation

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