Ultra-soft coatings for interfaces with brain and other soft tissues

A method of making an implant, comprising:

• selecting PDMS precursors;
• cross-linking the PDMS precursor to obtain an elastic modulus of about 3-9 kPa or +/−1%, 5%, 10%, 20%, or 50% and a short-term relaxation time-constant of about 10-20 sec or +/−1%, 5%, 10%, 20%, or 50%;
• selecting the carbon nanotubes;
• introducing the carbon nanotubes into the crosslinked PDMS to form a soft conductive composite composition;
• and
• coating the soft conductive composite composition onto at least a portion of an implant.

A method of measuring properties at a neural interface, the method comprising:

• providing a neural probe having a soft conductive composition, the soft conductive composition comprising a cross-linked silicone composition containing a plurality of carbon nanotubes;
• implanting the neural probe having the soft conductive composition at a neural interface;
• and
• measuring a property with the neural probe.

A method of making a tissue compatible implantable composition, comprising:

• selecting a tissue to receive the implant;
• determining an elastic modulus and short-term relaxation time-constant of the tissue;
• selecting PDMS precursors;
• and
• cross-linking the PDMS precursor to obtain the elastic modulus of the tissue or +/−1%, 5%, 10%, 20%, or 50% to obtain the tissue compatible implantable composition.