 This paper presents a novel approach to creating a flexible capacitive pressure sensor that has excellent linearity over a wide pressure range, high sensitivity, and ultra-high pressure resolution under large pressure preloads. This sensor uses an ultra-thin ionic layer to improve its performance, which allows it to detect subtle pulses, interact with robotic hands, and measure extremely precise weights. Additionally, the authors provide a detailed description of their fabrication process and design toolkit, making it easy to customize the sensor for different applications. This article was authored by Ruroshi Yang, Ankan Dutta, Bowen Lee, and others.