Insights into the Design and Manufacturing of On-Chip Electrochemical Energy Storage Devices
With the general trend of miniaturization of electronic devices especially for the Internet of Things (IoT) and implantable medical applications, there is a growing demand for reliable on-chip energy and power sources. Such tiny modules are expected to occupy no more than footprint-sized areas of a few square millimeters so that they can be easily integrated on semiconductor chips, while manufactured and packed using compatible approaches with current semiconductor processing. They are designed to provide power in the range of several µW to hundreds of mW and energy in the range of several hundreds of µWh to several mWh. Along with other emerging power sources such as miniaturized energy harvesters which cannot work alone, various miniaturized on-chip Electrochemical Energy Storage (EES) devices, such as micro-batteries and micro-supercapacitors, have been developed in the last two decades to store the generated energy and respond appropriately at peak power demand. One of the promising designs for onchip EES devices is based on interdigitated three-dimensional (3D) microelectrode arrays, which in principle could decouple the energy and power scaling issues. The purpose of this summary article is to give a generic view of our recent works on designing and manufacturing on-chip miniaturized EES devices in particular 3D EES devices based on carbon microelectromechanical systems (C-MEMS) [1-6]. We also discuss some emerging opportunities in both materials and manufacturing for such applications.