1 Departments of Materials Science and Engineering, Biomedical Engineering, Neurological Surgery, Chemistry, Mechanical Engineering, Electrical Engineering and Computer Science, Simpson Querrey Institute and Feinberg Medical School, Center for Bio-Integrated Electronics, Northwestern University, Evanston, Illinois, 60208, USA.
2 Innovative Center for Flexible Devices (iFLEX), Max Planck - NTU Joint Lab for Artificial Senses, School of Materials Science and Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore, 639798, Singapore.
3 Applied Mechanics Laboratory, Department of Engineering Mechanics, Center for Flexible Electronics Technology, Tsinghua University, Beijing, 100084, China.