1. Department of Electrical Engineering, Faculty of Engineering, Universiti Malaya, Kuala Lumpur 50603, Malaysia
2. Centre of Printable Electronics, Research Management & Innovation Complex, Universiti Malaya, Kuala Lumpur 50603, Malaysia
3. Department of Physics, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia
4. Universiti Malaya Centre for Ionic Liquid (UMCIL), Universiti Malaya, Kuala Lumpur 50603, Malaysia
5. Physics Division, Centre for Foundation Studies, Universiti Malaya, Kuala Lumpur 50603, Malaysia
6. School of System Design and Intelligent Manufacturing, Southern University of Science and Technology, Shenzhen 518055, China