Electrochemically-driven actuators electrode

The twisting nanotube yam actuators based on first principle mentioned above enable fully dry torsional actuation as the main driving mechanisms are based on electrothermal and/or photothermal effects. These actuators do not require electrolyte, counter electrode, or extra package as it is needed for electrochemically driven actuators (Chun et al. 2014). Indeed, the electroactivity of nanotube yams were firstly described in setup where bundled fibers were immersed in electrolyte the overall capability of twisting of actuators was demonstrated later without ion... 

The introduction of carbonaceous electrode materials for the electrochemically driven actuators intersected two classes of electrochemical devices that were considered as being separate beforehand - the electromechanical actuators and the electric double-layer capacitors (also known as supercapacitors). Although the... 

The capacitive nature of the electrochemically driven actuators with carbonaceous electrodes is of particular importance to consider when starting experimentation with this type of actuators - the capacitive properties of the actuators determine the most suitable driving waveform and characterization methods. 

In the selection of carbons for use as the electrode material in electrochemically driven actuators, the primary factor of choice is the specific siuface area of the carbons. Generally, an actuator that has higher capacitance also has higher actuation performance however, this principle is vahd in the extent of the same electrode material only (Palmre et al. 2009). 

Electric conductivity along the carbon filament in case of the electrothermally driven actuators, and along individual electrodes in case of the electrochemically driven actuators, is an important characteristic that has a large impact on the speed of the actuators, as it is explained in Sect. 2.2. Conductivity of an electrode can be measured using four-point measurement setup. Alternatively, voltage drop along an eleetrode during actuation can be used to estimate its conductivity (Kruusamae etal. 2012). 

Bohm S, Olthuis W, Bergveld P (2000) A bi-directional electrochemically driven micro liquid dosing system with integrated sensor/actuator electrodes. In IEEE MEMS workshop (MEM OO), pp 92-95... 

Carbon is a distinctive electrode material for actuators, as it is available in a wide variety of forms, ranging from monoliths to powders, fibers, and yams. The diversity in the properties of different carbonaceous materials is also expressed in a variety of actuation mechanisms. This chapter considers two classes of actuators - electrochemically and electrothermally driven actuators - which both make use of carbonaceous materials as active elements. In both of the listed types of actuators, carbon is especially advantageous because of its chemical and... 

Biochemical analysis on nanoliter scale is precisely carried out by micrototal analysis system (pTAS) which consists of microreactors, microfluidic systems, and detectors. Performance of the pTAS depends on micromachined and electrochemically actuated micropump capable of precise dosing of nanoliter amounts of liquids such as reagents, indicators, or calibration fluids [28]. The dosing system is based on the displacement of the liquid from a reservoir which is actuated by gas bubbles produced electrochemically. Electrochemical pump and dosing system consist of a channel structure micro-machined in silicon closed by Pyrex covered with novel metal electrodes. By applying pulsed current to the electrodes, gas bubbles are produced by electrolysis of water. The liquid stored in the meander is driven out into the microchannel structure due to expansion of gas bubbles in the reservoir as shown in Fig. 11.8. 

Sun Zh, Agafonov VM (2010) 3D numerical simulation of the pressure-driven flow in a four-electrode rectangular micro-electrochemical accelerometer. Sensors Actuators B Chem 146 231-238. www.elsevier.com/ locate/snb... 

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