m8ta
you are not logged in, login. new entry
text: sort by
tags: modified
type: chronology
{1395}
hide / edit[0] / print
ref: -0 tags: Courtine e-dura PDMS silicone gold platinum composite stretch locomotion restoration rats date: 12-22-2017 01:59 gmt revision:0 [head]

PMID-25574019 Biomaterials. Electronic dura mater for long-term multimodal neural interfaces.

  • Fabrication:
    • 120um total PDMS thickness, made through soft lithography, covalent (O2 plasma) bonding between layers
    • 35nm of Au (thin!) deposited through a stencil mask.
    • 300um Pt-PDMS composite for electrode sites, deposited via screenprinting
  • 100 x 200um cross section drug delivery channel.
  • Compared vs. stiff 25um thick PI film electrode.
    • stiff implants showed motor impairments 1-2 weeks after implantation.
  • Showed remarkable recovery of supported locomotion with stimulation and drug infusion (to be followed by monkeys).

{1267}
hide / edit[5] / print
ref: -0 tags: stretchable nanoparticle conductors gold polyurethane flocculation date: 12-13-2013 02:12 gmt revision:5 [4] [3] [2] [1] [0] [head]

PMID-23863931 Stretchable nanoparticle conductors with self-organized conductive pathways.

  • 13nm gold nanoparticles, citrate-stabilized colloidal solution
    • Details of fabrication procedure in methods & supp. materials.
  • Films are prepared in water and dried (like paint)
  • LBL = layer by layer. layer of polyurethane + layer of gold nanoparticles.
    • Order of magnitude higher conductivity than the
  • VAF = vacuum assisted floculation.
    • Mix Au-citrate nanoparticles + polyurethane and pass through filter paper.
    • Peel the flocculant from the filter paper & dry.
  • Conductivity of the LBL films ~ 1e4 S/cm -> 1e-6 Ohm*m (pure gold = 2 x 10-8, 50 x better)
  • VAF = 1e3 S/cm -> 1e-5 Ohm*m. Still pretty good.
    • This equates to a resistance of 1k / mm in a 10um^2 cross-sectional area wire (2um x 5 um, e.g.)
  • The material can sustain > 100% strain when thermo-laminated.
    • Laminated: 120C at 20 MPa for 1 hour.
  • See also: Preparation of highly conductive gold patterns on polyimide via shaking-assisted layer-by-layer deposition of gold nanoparticles
    • Patterned via MCP -- microcontact printing(aka rubber-stamping)
    • Bulk conductivity of annealed (150C) films near that of pure gold (?)
    • No mechanical properties, though; unlcear if these films are more flexible / ductile than evaporated film.