Fast Electrochemical Actuator with Ti Electrodes in the Current Stabilization Regime.

Ilia V Uvarov,Artem E Melenev,Vitaly B Svetovoy

doi:10.3390/mi13020283

Abstract

The actuators needed for autonomous microfluidic devices have to be compact, low-power-consuming, and compatible with microtechnology. The electrochemical actuators could be good candidates, but they suffer from a long response time due to slow gas termination. An actuator in which the gas is terminated orders of magnitude faster has been demonstrated recently. It uses water electrolysis performed by short voltage pulses of alternating polarity (AP). However, oxidation of Ti electrodes leads to a rapid decrease in the performance. In this paper, we demonstrate a special driving regime of the actuator, which is able to support a constant stroke for at least 10 cycles. The result is achieved using a new driving regime when a series of AP pulses are interspersed with a series of single-polarity (SP) pulses. The new regime is realized by a special pulse generator that automatically adjusts the amplitude of the SP pulses to keep the current flowing through the electrodes at a fixed level. The SP pulses increase the power consumption by 15–60% compared to the normal AP operation and make the membrane oscillate in a slightly lifted position.

Highlights

Microfluidic systems are widely used in biology, chemistry, and medicine for cell culturing and manipulation [1,2], synthesis of materials [3,4], pathogen detection [5,6], and other purposes
We apply a series of alternating polarity (AP) pulses to a “fresh” actuator and drive it in the normal regime for an hour, while the SP pulses are not used during the passive time
A new driving regime of the fast electrochemical actuator has been demonstrated in which the time interval between the series of AP pulses is filled with SP pulses

Summary

Introduction

Microfluidic systems are widely used in biology, chemistry, and medicine for cell culturing and manipulation [1,2], synthesis of materials [3,4], pathogen detection [5,6], and other purposes. One of the recent advances in microfluidics is implantable drug delivery modules, which provide controlled release of the drug directly to the target organ or tissue, bypassing the physiological barriers of the body [7,8,9,10]. These modules require a built-in pump that pushes the liquid through the microneedle. A constant voltage applied to the electrodes induces the electrochemical process. When the voltage is turned off, the gases recombine back into water and the membrane returns to its initial position

Methods

Results

Conclusion