Structural Modulation And Sensing Application Of Iontronic Pressure Sensor

Flexible pressure sensors are the core element of sensing in electronic skin systems and an essensital component of Io T-based environmental sensing.The rapid development of industrial fields such as smart health,big data,and Io T has increased demand for pressure sensors that can accurately sense the environment in daily life and complex scenes.This demand has raised the bar for pressure sensors regarding sensitivity,detection limit,and detection range.As a result,pressure sensor technology is constantly being improved to meet these higher expectations and provide better performance.Recent research into sensitive material systems and device structure design has led to the development of various types of flexible pressure sensors.However,the conflict between range and sensitivity is still one of the main challenges to improving the performance of these devices.This thesis proposes a definable iontronic flexible pressure sensor design inspired by biological structures to tackle the challenge of combining a wide range and high sensitivity in flexible pressure sensors.The innovative design has the potential to overcome the current limitations and advance the development of flexible pressure sensors.The device utilizes ionic gel as the pressure-sensitive material and incorporates a self-filling microstructure with interlocking characteristics.This design effectively enhances the structural compressibility and can adjust the initial capacitance and threshold pressure,resulting in improved performance.The device’s self-filling microstructures are built on the ionic gel surfaces of the upper and lower electrodes.It improves the compressibility of the gel dielectric layer by allowing the gel to fill the grooves of the microstructure when the device is deformed under pressure,thus avoiding premature saturation and compression of the ionic gel,which causes the device’s range to be too small.Furthermore,the microstructure increases the effective contact area of the ionic gel interface,thereby enhancing the device’s sensitivity.By building a spacer layer with an interlocking effect,the device’s initial capacitance and threshold pressure can be effectively adjusted to achieve a configurable range and sensitivity.The experimental results show that the flexible pressure sensor designed and prepared in this thesis can have an ultra-high sensitivity of 1478.8 k Pa^-1 in the normal pressure range（<100 k Pa）and maintain a high sensitivity above 337.8 k Pa^-1 in the wide pressure range（100 k Pa～400 k Pa）.And the device exhibits good repeatability.The performance of the device was analyzed by systematically characterizing the initial capacitance,start-up threshold,and capacitive response of devices with different spacer layer structures and their heights.This analysis helped establish a constitutive relationship between the ionic gel-based interlocking self-filling microstructure and device performance.On this basis,the application of the device in human motion monitoring and touch interaction is further explored.By placing the single device at the forefoot position,the detection of daily postures,such as sitting,squatting,and standing postures,as well as the motion states,such as walking,running,and jumping,can be achieved through the acquisition and analysis of the device capacitance.By constructing the sensors array,the device can sense of pressure magnitude and position by analyzing the difference in capacitance change of each sensitive unit.The experimental results show that the designed and prepared sensors array can realize the detection and judgment of different letter templates such as"P","A",and"D",and also the detection of the fingertip by the multi-touch capability of the magnitude and position of the applied gentle,normal and strong pressure.This study can provide a feasible new idea for the device performance tuning of flexible pressure sensors.