Four-electrode micropump with peristaltic motion

• A peristaltically and electrostatically driven micropump for gas chromatography.
• Optimization of the driving parameters to increase the pump rate (4 times improvement).
• Maximum flow rate: a basic actuating signal was about 38 μl/min at 90 V at 15 Hz.
• Maximum flow rate: an optimized actuating signal was about 136 μl/min 90 V at 15 Hz.

We present an electrostatically driven four-electrode micropump that operates with peristaltic motion. The working fluid is gas. In particular, we focus on the characteristics of the micropump as a function of the various actuating signals for four flexible electrodes. The micropump operated between 60 V and 120 V with a customized pulse signal. Whereas the maximum flow rate using a basic actuating signal was approximately 38 μl/min at 90 V and 15 Hz, the maximum flow rate using an optimized actuating signal was approximately 136 μl/min at 90 V and 15 Hz. This is an increase of approximately 3.6 times the minimum flow rate. Various actuating signals were generated from a microcontroller unit (MCU) equipped with a logic circuit and a high-voltage DC power supply and function generator. The minimum flow rate occurs with a four pumping sequence with three electrodes. However, the maximum flow rate occurs when these four electrodes participate sequentially. The proposed micropump consists of only a single chamber and a flexible membrane with four electrodes. The chamber is divided into smaller cells with the embedded electrodes controlled by a custom-made logic circuit that generates various phase-sequencing actuation signals. This micropump is applicable for gas chromatography.