1. Integrated Electronics and Biointerfaces Laboratory, Department of Electrical and Computer Engineering, University of California San Diego, La Jolla, CA 92093, USA.
2. Department of Neurological Surgery, University of California San Diego, La Jolla, CA 92093, USA.
3. Department of Neurological Surgery, Oregon Health and Science University, Portland, OR 97239, USA.
4. Department of Obstetrics, Gynecology, and Reproductive Sciences, Center for Reproductive Science and Medicine, University of California San Diego, La Jolla, CA 92093, USA.
5. Department of Neurology, Massachusetts General Hospital, Boston, MA 02114, USA.
6. Department of Neurosurgery, Massachusetts General Hospital, Boston, MA 02114, USA.
7. Graduate Program of Materials Science and Engineering, University of California San Diego, La Jolla, CA 92093, USA.