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All-carbon-nanotube flexible multi-electrode array for neuronal recording and stimulation.

David-Pur M, Bareket-Keren L, Beit-Yaakov G, Raz-Prag D, Hanein Y - Biomed Microdevices (2014)

Bottom Line: The use of carbon nanotubes bestows the electrodes flexibility and excellent electrochemical properties.As opposed to contemporary flexible neuronal electrodes, the technology presented here is both robust and the resulting stimulating electrodes are nearly purely capacitive.Recording and stimulation tests with chick retinas were used to validate the advantageous properties of the electrodes and demonstrate their suitability for high-efficacy neuronal stimulation applications.

View Article: PubMed Central - PubMed

Affiliation: School of Electrical Engineering, Tel-Aviv University, Tel-Aviv, 6997801, Israel.

ABSTRACT
Neuro-prosthetic devices aim to restore impaired function through artificial stimulation of the nervous system. A lingering technological bottleneck in this field is the realization of soft, micron sized electrodes capable of injecting enough charge to evoke localized neuronal activity without causing neither electrode nor tissue damage. Direct stimulation with micro electrodes will offer the high efficacy needed in applications such as cochlear and retinal implants. Here we present a new flexible neuronal micro electrode device, based entirely on carbon nanotube technology, where both the conducting traces and the stimulating electrodes consist of conducting carbon nanotube films embedded in a polymeric support. The use of carbon nanotubes bestows the electrodes flexibility and excellent electrochemical properties. As opposed to contemporary flexible neuronal electrodes, the technology presented here is both robust and the resulting stimulating electrodes are nearly purely capacitive. Recording and stimulation tests with chick retinas were used to validate the advantageous properties of the electrodes and demonstrate their suitability for high-efficacy neuronal stimulation applications.

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All-CNT flexible multi-electrode arrays. a Electrode fabrication scheme. (1) The process is based on a single photolithographically defined Ni catalyst layer. (2) The CNT film is then grown using a CVD process. (3) Next, the film is transferred to a polymeric support (e.g. medical adhesive tape, PDMS, Parylene C, polyimide). (4) Finally, a second polymeric layer (PDMS) with predefined holes is bonded with the CNT carrying film for passivation. b Different patterns of flexible CNT electrode arrays on different support layers: (1) PDMS, (2) medical adhesive tape, (3) Parylene C and (4) polyimide
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Fig1: All-CNT flexible multi-electrode arrays. a Electrode fabrication scheme. (1) The process is based on a single photolithographically defined Ni catalyst layer. (2) The CNT film is then grown using a CVD process. (3) Next, the film is transferred to a polymeric support (e.g. medical adhesive tape, PDMS, Parylene C, polyimide). (4) Finally, a second polymeric layer (PDMS) with predefined holes is bonded with the CNT carrying film for passivation. b Different patterns of flexible CNT electrode arrays on different support layers: (1) PDMS, (2) medical adhesive tape, (3) Parylene C and (4) polyimide

Mentions: We investigated a new fabrication technique utilizing a combination of micro and nano schemes to realize non-Faradaic CNT based electrodes with very high specific capacitance using a simple fabrication process. To support a simple and robust fabrication process, the electrodes are made exclusively of CNTs so no complex fabrication integration was required. The general fabrication process, described in Fig. 1a, is based on loosely-bound MWCNT films grown using CVD process from a thin Ni layer (Fig. 1a-2). The Ni layer is deposited on a support Si/SiO2 substrate (Fig. 1a-1). An uncured polymer (e.g. PDMS or polyimide) is then casted on the substrate with the CNT film. After curing, the CNTs are integrated with the polymer. The polymer and the CNT films can then be peeled-off from the surface (Fig. 1a-3). Similar results can be obtained by applying an adhesive tape against the CNT pattern or by using vapor deposition of Parylene C. The CNT carrying film and a second layer of holey PDMS membrane are then bonded together (Fig. 1a-4) to form a flexible circuit containing passivated CNT conducting tracks and exposed CNT electrodes. The biocompatibility of PDMS, parylene C and polyimide is well established. Polyimide and parylene C have comparable elastic moduli of ~2–4 GPa (two to three orders of magnitude lower than that of metal and silicon), while PDMS elasticity (depending on preparation conditions) can be further reduced down to ~0.05 MPa (Rousche et al. 2001; Brown et al. 2005; Rodger et al. 2008; Meacham et al. 2011). Polyimide can be patterned using standard microfabrication such as photolithography and reactive ion etching (Cheung et al. 2007; Mercanzini et al. 2008) and parylene C has superior resistance to moisture. Finally, the adhesive medical tape enables quick and simple fabrication with well exposed CNT films. Such films may be well suited for skin-applied electrode arrays.Fig. 1


All-carbon-nanotube flexible multi-electrode array for neuronal recording and stimulation.

David-Pur M, Bareket-Keren L, Beit-Yaakov G, Raz-Prag D, Hanein Y - Biomed Microdevices (2014)

All-CNT flexible multi-electrode arrays. a Electrode fabrication scheme. (1) The process is based on a single photolithographically defined Ni catalyst layer. (2) The CNT film is then grown using a CVD process. (3) Next, the film is transferred to a polymeric support (e.g. medical adhesive tape, PDMS, Parylene C, polyimide). (4) Finally, a second polymeric layer (PDMS) with predefined holes is bonded with the CNT carrying film for passivation. b Different patterns of flexible CNT electrode arrays on different support layers: (1) PDMS, (2) medical adhesive tape, (3) Parylene C and (4) polyimide
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC3921458&req=5

Fig1: All-CNT flexible multi-electrode arrays. a Electrode fabrication scheme. (1) The process is based on a single photolithographically defined Ni catalyst layer. (2) The CNT film is then grown using a CVD process. (3) Next, the film is transferred to a polymeric support (e.g. medical adhesive tape, PDMS, Parylene C, polyimide). (4) Finally, a second polymeric layer (PDMS) with predefined holes is bonded with the CNT carrying film for passivation. b Different patterns of flexible CNT electrode arrays on different support layers: (1) PDMS, (2) medical adhesive tape, (3) Parylene C and (4) polyimide
Mentions: We investigated a new fabrication technique utilizing a combination of micro and nano schemes to realize non-Faradaic CNT based electrodes with very high specific capacitance using a simple fabrication process. To support a simple and robust fabrication process, the electrodes are made exclusively of CNTs so no complex fabrication integration was required. The general fabrication process, described in Fig. 1a, is based on loosely-bound MWCNT films grown using CVD process from a thin Ni layer (Fig. 1a-2). The Ni layer is deposited on a support Si/SiO2 substrate (Fig. 1a-1). An uncured polymer (e.g. PDMS or polyimide) is then casted on the substrate with the CNT film. After curing, the CNTs are integrated with the polymer. The polymer and the CNT films can then be peeled-off from the surface (Fig. 1a-3). Similar results can be obtained by applying an adhesive tape against the CNT pattern or by using vapor deposition of Parylene C. The CNT carrying film and a second layer of holey PDMS membrane are then bonded together (Fig. 1a-4) to form a flexible circuit containing passivated CNT conducting tracks and exposed CNT electrodes. The biocompatibility of PDMS, parylene C and polyimide is well established. Polyimide and parylene C have comparable elastic moduli of ~2–4 GPa (two to three orders of magnitude lower than that of metal and silicon), while PDMS elasticity (depending on preparation conditions) can be further reduced down to ~0.05 MPa (Rousche et al. 2001; Brown et al. 2005; Rodger et al. 2008; Meacham et al. 2011). Polyimide can be patterned using standard microfabrication such as photolithography and reactive ion etching (Cheung et al. 2007; Mercanzini et al. 2008) and parylene C has superior resistance to moisture. Finally, the adhesive medical tape enables quick and simple fabrication with well exposed CNT films. Such films may be well suited for skin-applied electrode arrays.Fig. 1

Bottom Line: The use of carbon nanotubes bestows the electrodes flexibility and excellent electrochemical properties.As opposed to contemporary flexible neuronal electrodes, the technology presented here is both robust and the resulting stimulating electrodes are nearly purely capacitive.Recording and stimulation tests with chick retinas were used to validate the advantageous properties of the electrodes and demonstrate their suitability for high-efficacy neuronal stimulation applications.

View Article: PubMed Central - PubMed

Affiliation: School of Electrical Engineering, Tel-Aviv University, Tel-Aviv, 6997801, Israel.

ABSTRACT
Neuro-prosthetic devices aim to restore impaired function through artificial stimulation of the nervous system. A lingering technological bottleneck in this field is the realization of soft, micron sized electrodes capable of injecting enough charge to evoke localized neuronal activity without causing neither electrode nor tissue damage. Direct stimulation with micro electrodes will offer the high efficacy needed in applications such as cochlear and retinal implants. Here we present a new flexible neuronal micro electrode device, based entirely on carbon nanotube technology, where both the conducting traces and the stimulating electrodes consist of conducting carbon nanotube films embedded in a polymeric support. The use of carbon nanotubes bestows the electrodes flexibility and excellent electrochemical properties. As opposed to contemporary flexible neuronal electrodes, the technology presented here is both robust and the resulting stimulating electrodes are nearly purely capacitive. Recording and stimulation tests with chick retinas were used to validate the advantageous properties of the electrodes and demonstrate their suitability for high-efficacy neuronal stimulation applications.

Show MeSH
Related in: MedlinePlus