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{1456}
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ref: -2011 tags: ttianium micromachining chlorine argon plasma etch oxide nitride penetrating probes Kevin Otto date: 03-18-2019 22:57 gmt revision:1 [0] [head]

PMID-21360044 Robust penetrating microelectrodes for neural interfaces realized by titanium micromachining

  • Patrick T. McCarthyKevin J. OttoMasaru P. Rao
  • Used Cl / Ar plasma to deep etch titanium film, 0.001 / 25um thick. Fine Metals Corp Ashland VA.
  • Discuss various insulation (oxide /nitride) failure modes, lithography issues.

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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).

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ref: -0 tags: polyimide epoxy potassium hydroxide etch adhesion date: 06-25-2015 00:28 gmt revision:0 [head]

Improvement in the adhesion of polyimide/epoxy joints using various curing agents

  • Used 1M KOH, ~2min, followed by 0.2M HCl for 6 min to ring-open the imide.
  • PMDA/ODA polyimide (Pyromellitic Dianhydride, single aromatic ring + 4,4 diamino diphenyl ether )
  • Epoxy of the DGEBA + linear amide or aromatic (3,3 methylenedianiline)
  • Best result was with a polyamide curing agent, and high-temp curing profile. Unlikely that this will work for us, parylene will decompose..

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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.

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ref: -0 tags: plasma etch removal parylene DRIE date: 05-28-2013 18:47 gmt revision:2 [1] [0] [head]

Plasma removal of Parylene C

  • Ellis Meng, Po-Ying Li and Yu-Chong Tai USC / Caltech
  • Technics O2 plasma etch works, as do DRIE / RIE etch; all offer varying degrees of anisotropy, with the more intricate processes offering straighter sidewalls.
  • Suggested parameters for O2 etch is 200sccm / 200W.
  • Etch will be somewhat isotropic -- top of photoresist will be etched away, leading to ~15deg sloped sidewalls.
    • Hence, small parylene features will be narrowed by the 02 plasma.

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ref: GULD-1964.07 tags: platinum iridium microelectrode eltrolytic etching original date: 01-03-2012 19:05 gmt revision:2 [1] [0] [head]

PMID-14199966[0] A Glass-covered platinum microelectrode

  • Details the manufacture and testing of PT-IR (70/30) etched solder glass-coated microelectrodes.
  • Melt a bead of the glass on the top and gradually draw the bead downward, surrounded by the heater of a pipette drawing machine.

____References____

[0] GULD C, A GLASS-COVERED PLATINUM MICROELECTRODE.Med Electron Biol Eng 2no Issue 317-27 (1964 Jul)