Carbon fiber optrodes for magnetic resonance imaging compatible optogenetics

An implantable device comprising an optrode comprising:

• a carbon fiber electrode having a first end and a second end, wherein the carbon fiber electrode has a diameter of from 10 μm to 180 μm;
• a metal wire or metal connector attached to the carbon fiber electrode at the first end;
• a ceramic stick ferrule having a third end and a fourth end, wherein the ceramic stick ferrule has a face at the third end, wherein the face has a first diameter less than a second diameter of the fourth end;
• and
• an optical fiber having a fifth end and a sixth end, wherein a portion of the optical fiber proximate the fifth end is located within the ceramic stick ferrule, wherein the optical fiber is inserted into a concave face of the ceramic stick ferrule such that the fifth end is level with the face of the third end of the ceramic stick ferrule, wherein the third end of the ceramic stick ferrule is configured to be coupled to a light source and a remaining portion of the optical fiber including the sixth end extends from the fourth end of the ceramic stick ferrule, wherein the optical fiber is secured within the ceramic stick ferrule by a first epoxy,
• wherein a first portion of the carbon fiber electrode proximate the second end is coupled to a portion of optical fiber proximate the sixth end by a second epoxy such that the portion of the carbon fiber electrode and the portion of the optical fiber are aligned parallel to one another and the second end of the carbon fiber electrode and the sixth end of the optical fiber are aligned such that neither the second end nor the sixth end extends further than the other and the second end and the sixth end are configured to be implanted in a subject,
• wherein a second portion of the carbon fiber electrode between the first portion and the first end is coupled to a portion of the ceramic stick ferrule proximate the fourth end by a third epoxy.