Woven Electrochemical Transistors on Silk Fibers

Abstract

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...

Multifunctional Biomimetic Scaffolds Tailored for Cardiac Regeneration

“…231 Coating of silk fibers 50-100 µm in diameter, has also been shown to be useful for fabrication of electrochemical transistors. 232 Addition of PEDOT-S during the growth step of collagen fibrils allowed for self-assembly of PEDOT-S coated collagen fibril, which could be imaged without conductive metal coatings in the electron microscope, Figure 30.…”

Weaving of Fabric for Meter-Scale Floor Touch Sensors Using Automatic Looming Machine

“…In the same way, manufacturing technology of a printed circuit board cannot provide meterscale pressure or touch sensors because the sizes are limited to several tens of centimeters and a large-area board is expensive. (14) Scalable fabrication technology for floor touch sensors (i.e., e-textile), (15)(16)(17) which is based on textile technology, has recently attracted much attention because automatic looming machines are considered a highly mature technology in use since the industrial revolution, which can produce several meter-wide fabrics continuously at a low cost. (15)(16)(17)(18)(19)(20)(21)(22) However, with the present technology, the sensor fibers have been woven manually, and there are few examples of automatic weaving of sensor fibers because the touch sensor fibers are sensitive to the destructive tension and friction produced by automatic looming machines.…”

“…(14) Scalable fabrication technology for floor touch sensors (i.e., e-textile), (15)(16)(17) which is based on textile technology, has recently attracted much attention because automatic looming machines are considered a highly mature technology in use since the industrial revolution, which can produce several meter-wide fabrics continuously at a low cost. (15)(16)(17)(18)(19)(20)(21)(22) However, with the present technology, the sensor fibers have been woven manually, and there are few examples of automatic weaving of sensor fibers because the touch sensor fibers are sensitive to the destructive tension and friction produced by automatic looming machines. (18)(19)(20)(21)(22) In fact, wrong tension is applied especially in the case of warp sensor fibers, resulting in threads being cut when the wefts are interlaced since the sensor fibers have a larger diameter than those of other conventional polyester or other fibers.…”

Fluorene-based macromolecular nanostructures and nanomaterials for organic (opto)electronics

“…Solution-processed nanoparticles with low viscosity are amenable to being printed into devices through low-cost and high-throughput inkjet or roll-to-roll printing techniques [78,81]. Jagannathan et al [223] demonstrated that organic nanoparticles are suitable for low-cost printing procedures.…”