Electret transducers utilize the electric field generated by an electret, a dielectric with a quasi-permanent embedded charge, to induce charge on an electrode. When the electret is moved relative to the electrode, the induced charge magnitude on the electrode changes, generating a current that can be used to convert mechanical energy into electrical energy. Micro-electret transducers are promising alternatives to conventional electromagnetic transducers for small-scale energy harvesting as they can achieve a high voltage output at low frequencies, can be miniaturized effectively, and can be manufactured using microfabrication methods.

One-dimensional electrostatic models have been developed to predict the power output of electret transducers. However, for micro-electret transducers, fringing fields play a large role in the electrostatic domain. To be able to more accurately predict the output characteristics of micro-electret transducers, a two-dimensional (2D) electrostatic model is proposed. To verify the 2D model, a novel micro-electret transducer is designed. The novel electret design allows the micro-electret transducer to embed charges of only one polarity, increasing the power output of the electret transducer.

The novel 2D model more accurately predicts the power output characteristics of the micro-electret transducer with the voltage output deviating 57%, compared with 317% by the conventional model predictions. Furthermore, the novel unipolar micro-electret transducer achieves double the power output and better charge stability compared with conventional electret transducers.

Biosensing properties like mass, density and stiffness on a single cell level can help diagnose diseases. Mass sensing of cells and subcellular components is typically performed with resonant microstructures. Recently such microstructures were fabricated using an emerging 3D printing technique called two-photon polymerization (2PP) contrary to conventional lithography-based fabrication. The suspended microchannel resonator (SMR) is such a resonant microstructure with an embedded fluidic channel for buoyant mass sensing, which has not yet been fabricated using 2PP. This work aims to 3D print an SMR with a sufficient mass resolution to detect the buoyant mass of E. Coli bacteria (175 fg in water). It was realized by first characterizing the damping in 3D printed polymer microbeam resonators for a better understanding of dominating damping sources. Followed by maximizing their quality factor and fabricating a prototype 3D-printed SMR. The characterized devices set a record-breaking standard for damping of polymer microbeam resonators: Cantilevers and bridges approached quality factors of 1000 and tensile stressed narrow bridges achieved a quality factor of 1819. These polymer resonators were dominated by bulk friction damping, but still had a mass resolution advantage over similar silicon-based devices when working in lower quality factor (Q < 1000) conditions, due to the low mass density of the polymer. Subsequently, prototypes of the suspended microchannel resonator were fabricated with multi-scale 3D printing containing a plug-and-play connection to fluidics and measurement equipment. Their theoretical mass resolution was estimated to be ≤ 60 fg, which is sensitive enough to detect E. Coli bacteria and compete with conventional fabricated SMRs. This paves the path towards actual biosensing 3D printed SMRs with the capabilities of lithography-based fabricated devices but with additional design and fabrication flexibility.

Facioscapulohumeral muscle dystrophy (FSHD) is the third most common muscle disease in the world. No cure has been found for FSHD, and current treatments focus on alleviating the symptoms. The disease is caused by a genetic error in 1/1000 - 1/200 of the nuclei in a multinucleated skeletal muscle cell. Studying that specific nucleus, by removing it from the cell, perform transcriptomics on it and determining the cell viability after the nucleus removal, can provide important information about FSHD.

In this work, a multiscale 3D printing approach was optimized to fabricate a microfluidic atomic force microscopy (AFM) cantilever that can remove a nucleus from a living cell. With the device mounted on an AFM system, cell experiments were performed, which showed that the nucleus can be removed from a cell using 3D printed microfluidic cantilevers. The printing methods can be used to fabricate various types of suspended microfluidic devices to perform single-cell biopsy and biophysical characterization of single-cells.

The processes that take place within cells are complex. Single-cell analysis is a method that is employed to gain further understanding of the working mechanisms on a single-cellular level. The controlled transport of substances through the cell membrane is important for studying the behaviour and responses of single living cells. Femtopipettes are used as a means to accurately target and sample cells with high viability rates. Different actuation principles exist for femtopipettes, but pressure actuation is identified as the most versatile and straightforward method. However, the volume dosing resolution of pressure driven femtopipettes lags behind other actuation methods. Throughout literature, the minimum reported dose is identified as 100 femtolitre (1 fL= 10^-15 L), achieved by applying a pressure pulse to a femtopipette. In this work, two new concepts are proposed and researched with the goal of increasing the volume dosing resolution of pressure driven femtopipettes. A multi-scale 3D printing strategy was employed where functional femtopipettes were successfully printed using two-photon-polymerization (2PP). The first concept incorporates a physical barrier in the form of a flexible membrane into the femtopipette. It was expected that the volume actuated by the deformation of the membrane could be controlled and calibrated. The deformation of 2PP printed membranes was characterized and the achieved volume displacement was well in the desired range of 100 fL. However, tests with liquid dosing did not succeed in achieving this same range, and difficulties were experienced with reproducibility. The second concept exploited the phenomenon of capillarity by incorporating axisymmetrical phaseguides as a means to control the position of the liquid-air meniscus. Consecutive geometrical steps were created that allowed for discrete and robust control over the liquid portion within the femtopipette. Step sizes of 10 picolitre (1 pL= 10^-12 L), 200 fL and 60 fL were fabricated and successfully tested, breaching beyond the current state of the art. This concept thus demonstrates both the level of customization and the unprecedented volume dosing resolution that was achieved.

The Atomic Force Microscope (afm) is a small scale measuring device, with a lot of benefits over other existing measuring techniques. Unfortunately, measurement speed is not one of them. Many have tried and succeeded to improve the measurement speed, but there is still room for improvement.
By passively lowering the Q-factor, a measurement can be sped up, while still be compatible with other speed improvement techniques.
To passively lower the Q-factor, we propose measuring in a medium more dense then air. First in a liquid, de-mineralized water, to prove the effect, and later in a gas, co2, to keep the samples clean.
Our models predict a speed increase of 0.3559 ms per measured point, or 6.941 min per image of 5 μm × 5 μm with 512 lines in liquid. The experiments show an increase of 0.4180 ms per point, or 8.155 min per measurement. In the much less dense gas a 0.031 01 ms per point or 0.6550 min per frame is calculated. The experiments show an increase of 0.027 29 ms per point with a total of 0.5300 min per frame.
Both in liquid and in gas an improvement is observed. When measuring in a liquid, the speed increase of 8.155 min per frame is noticeable when a small area on a single sample is measured. Measurements in gas, with an increase of 0.5300min per frame only become interesting when multiple frames need to be measured, since a gas measurement does take longer to set up. Changing the used measurement gas to a more dense gas could make single frame measurements more interesting.

Atherosclerotic plaque rupture is the main cause of acute myocardial infarction and stroke, the two leading causes of death worldwide. Rupture of plaque tissue is a mechanical event, where plaque stress or strain locally exceeds its strength. Biomechanical studies agree with histopathological findings that a large lipid pool and thin fibrous cap overlying the lipid pool increase the likelihood of rupture, by showing increased plaque stresses for these geometries. Another plaque morphological feature that is frequently encountered is calcification. However, its role in the vulnerability of plaques to rupture is not fully understood, and biomechanical modeling studies do not agree on the effect of calcifications on plaque stress. These studies used isotropic material properties for the anisotropic and collagen rich plaque tissue, and generally focused on the effect of calcification on lumen stress or cap stress. However, histopathological findings revealed tissue damage at the interface between calcification and surrounding tissue.

This study investigated stresses and strains at the interface between calcification and fibrous tissue, how these stresses and strains are influenced by local anisotropy of the fibrous tissue and how geometric features of the calcification are related to these metrics. A morphometric study was conducted first, to investigate and categorize different patterns of fiber alignment around the calcifications, and to measure the calcification geometric features including its location in the plaque, its shape and its size. Biomechanical models including the local anisotropic material properties were constructed next, based on the observations and measurements made in the morphometric analysis. Stress and strain metrics were investigated at the calcification boundary, and subsequently related to fiber patterns and calcification geometric features.

Hundred forty five calcifications were segmented and measured in the morphometric analysis, and surrounding fiber alignments were studied. The analysis revealed that four main fiber patterns in the fibrous tissue surrounding calcifications exist: the Attached pattern, Pushed Aside pattern, Encircling pattern and Random pattern. Collagen fibers are attached to the calcification in the Attached pattern, are pushed aside by the calcification in the second pattern, encircle the calcification in the third pattern, and show a disorganized alignment in the Random pattern. The Attached pattern was the most prevalent fiber pattern, and its corresponding calcifications had larger aspect ratios and were on average larger than the other three fiber patterns. Large peak stresses and strains at the calcification boundary were identified in the biomechanical models for the Attached pattern and Pushed Aside pattern, while these metrics showed generally lower peak values for the Encircling pattern and Random pattern. Peak values for all stress and strain metrics were attained at the tip of the calcifications. Multivariate analysis showed that stresses and strains are related to the calcification geometric features; calcification interface stress and strain increased if the calcification was closer to the lumen, had a larger length/width ratio and was larger in size.

Histopathological examination of plaques evidenced damage at the interface between calcification and fibrous tissue, potentially caused by an adverse mechanical state at this boundary. Most studies focused on stresses at the lumen or in the cap however, and this study for the first time specifically investigated stresses and strains at the calcification boundary while simultaneously introducing local fibrous tissue anisotropy in the computational models. Results show that peak stresses and strains can develop at this boundary, which will remain undiscovered if isotropic materials are used. This study was also the first to extensively analyze calcification geometric features and surrounding fiber alignment in relation to these interface stresses and strains. Peak values were found to be dependent on these features and fiber alignment patterns, indicating a relation between these characteristics and mechanical stability of the plaque. The findings of this study further increase the clinical relevance of finite element modeling in rupture risk prediction by showing previously undiscovered peak stress and strain values for interfaces and geometric configurations which already were deemed to be destabilizing in clinical and histopathological studies.

In the past few decades, there has been a growing demand for low-cost disposable sensors to be utilized in hazardous and toxic environments such as high temperature and chemically aggressive environments, which can lead to irreversible damage to the sensor. Moreover, by cost reduction, they become more attractive for utilization in developing countries, where the research of new biomedical technologies has been restricted due to a decentralized healthcare system, lack of infrastructure and shortage of investment. This research focuses on developing a low-cost, disposable and easy to use mass sensor utilizing diamagnetic levitation. Diamagnetic levitation is the only stable form of levitation at room temperature and does not require external sources of energy, feedback loops or cooling for stable levitation. It is a low cost, easy to use, disposable sensor that makes it suitable for potential point-of-care applications. The sensor consists of a pyrolytic graphite plate that levitates above a checkerboard arrangement of permanent magnets with alternating magnetization. The system is actuated using electromagnetic excitation and the material properties of the sample are extracted by conducting a multi-modal analysis of the resonance frequencies and mode shapes; measured using a laser Doppler vibrometer (LDV). An opto-electronic phase lock loop utilizing the LDV is used to bring the levitating pyrolytic graphite into sustained mechanical oscillation controlled by a PID controller. The experimental mass sensitivity is measured by analysing the frequency shift associated with the placement of glass beads. The frequency stability is measured by computing the Allan deviation and the experimental precision of mass sensor is then computed. The results show that the precision of a diamagnetically levitated resonant mass sensors decreases with the decrease of the size of the levitating oscillator. The precision of a levitating oscillator of side length 2mm and thickness 0.08mm is found to be 14.4pg at a gate time of 0.1s for an instantaneous change in frequency.

In the last few years organ-on-chip (OoC) has been emerging as a new method for more reliable research to screen the effects of new drugs on the body. This is a novel technology mimicking the in vivo environment of tissue cells, making it a more suitable candidate for experimentation than traditional 2D cell cultures. However, in order to ensure smooth and swift implementation of this technique, some issues must be addressed first. One of these issues concerns perfusion: most OoC devices require external equipment to provide the necessary dynamic flow that makes the OoC unique, so that cells experience continuous fluid shear and are perfused sufficiently. In this thesis a model of an on-chip electro-polymeric pump is designed for application on an OoC. From a background study the design aims are defined: a membrane actuated pump with a nozzle-diffuser channel providing pump action. The membrane is made from ionic polymer-metal composite (IPMC), a material that deforms under electric current which is produced at TU Delft with the intention to use it in OoC applications. Its low voltage operating range and its biocompatibility make it an excellent candidate for this. Furthermore, the nozzle-diffuser elements avoid the need for moving elements inside the channel, instead providing pump action based on a pressure gradient over the nozzle elements. Finally, three design aims are defined, being: high flowrate, high flow pulse and low flow rate and pulse applications, corresponding to various needs in the OoC field. A base model is designed using COMSOL Multiphysics software, using similar devices described in literature. The model consists of a combination of solid mechanics (for membrane movement), fluid mechanics (for flow movement) and a fluid-structure interaction module to combine the two. This model is then tested for a range of parameters, first independently and later in pairs. General conclusions drawn from these simulations include: - Between the membrane displacement and -frequency (which can both be varied after fabrication), the membrane displacement magnitude affects the output more significantly than actuation frequency - The membrane width is positively correlated with flow rate output and pulse amplitude - The channel depth is positively correlated with flow rate output, but only if the membrane displacement scales along with it - A long slender nozzle yields lower flow output than a short, squat nozzle - The results from this model are consistent with nozzle-diffuser theory, stating that nozzle resistance and membrane movement affect the flow most significantly. This leads to three designs according to the three application wishes expressed earlier. The pump is designed such that it can be manufactured on a silicon wafer using electronics cleanroom equipment. The combination with the process developed for IPMC provides a novel pumping mechanism that has the potential to fully integrate an important aspect of an OoC on-chip, greatly increasing user friendliness and allowing for wider implementation of this technology.

Photonics biosensors convert biomolecular interactions into quantifiable optical signals for biomedical analysis, which enable continuous monitoring of health indicators. Among them the microring resonator has a good sensing performance and a very broad application prospect. This thesis studies sensing with microfluidic integrated microring resonator photonic microchips.
This thesis adopts finite element method to simulate the optical behavior of waveguides and reactions in the microfluidic channel. The microfluidic channel was designed and prepared and then integrated to the photonic chip. The optical performance parameters of the micro ring resonator were tested by using a high-precision optical test system. The sensing performance of waveguide microring was studied using different aqueous solution as the detection object. The feasibility and effectiveness of the optical waveguide chip sensing have been preliminary verified.

Small satellites require efficient propulsion systems for attitude and orbit control. This thesis focuses on the development and characterization of two distinct types of micro-resistojet thrusters, namely Vaporizing Liquid Micro-resistojet (VLM) and Low Pressure Micro-resistojet (LPM). Both concepts are developed at TU Delft and are designed to use water as a propellant, conforming to launch-safety, simplicity, and cost-effectiveness criteria.
In VLM, liquid water is vaporized and accelerated through a convergent-divergent nozzle. In contrast, LPM operates by reducing water vapor pressure to below 300 Pa and then accelerating it through expansion slots under a rarefied flow regime. Both types of thrusters are built on Micro-Electro-Mechanical Systems (MEMS) chips to accommodate the size constraints of nano- and pico-satellites.
The thesis introduces refined designs for both VLM and LPM thrusters. Specifically, the VLM design features an optimized nozzle shape and improved inlet flow, while the redesigned LPM assembly is more space-efficient. These modifications increase the thrust-to-size ratio for both thruster types.
The thesis presents a fabrication process for these thrusters, employing an anodic bonded silicon-glass wafer stack with a capped microfluidic channel. Fabrication was executed at the EKL lab, using a simplified manufacturing process that is detailed within the report.
Post-fabrication, the thrusters underwent mechanical and electrical characterization. The results indicate incremental improvements in both design performance and manufacturability. The new VLM design yielded a 15% increase in thrust efficiency, while the new LPM assembly reduced the occupied volume by 30%.

Single photon detectors are an important optical sensing tool in many industries. However, these highly efficient detectors suffer from variations in the size of an optical cavity when cooling down to 3K. An active positioning system is therefore required to correct the relative position of the fibre to the detector, so an optimal and reproducible cavity size can be achieved, thereby maximizing their efficiency. The literature study performed on cryogenic precision actuators showed that a stepper motor in combination with a motion reduction mechanism is the most feasible design. A stepper motor and a precision screw were two fundamental components of the preliminary design, so their lubrication was removed and were proven to work cryogenically. The rest of the design was based around these fundamental components. Room temperature tests were done to show the functionality of the design and it showed a positioning resolution between 10 nm and 30nm with just a 100nm loss of motion when unloading and loading the system. Cryogenic tests achieved similar results and it showed that the reflected power of a detector was reduced from 8.8% to 3.6%, indicating that the maximum achievable detector efficiency increased from 91.2% to 96.4%.

Much research is conducted on the biomechanical properties of cells, particularly in cancer research. Cell stiffness and cell adhesion are two properties often studied, because they are important for the functioning of a cell. To study these properties, atomic force microscopy(AFM) is often used, using nanoindentation for stiffness analysis and fluid force microscopy(FluidFM) for adhesion analysis. However, these techniques often involve different cantilever probes, which complicates the measurement of both properties in a single cell. To make it possible to study cell stiffness and cell adhesion of a single cell, a multifunctional microfluidic AFM cantilever is developed in this research. This cantilever is equipped with a blunted pyramid-shaped tip for nanoindentation enabling the measurement of cell stiffness and imaging. Moreover, it features a channel running through its length, with an aperture on the tip, facilitating fluid force microscopy for determining cell adhesion. The multifunctional cantilever is fabricated using a multiscale 3d-printing technique, where stereo lithography is used for the larger parts, and two-photon polymerisation is used for the cantilever. To demonstrate the capabilities of the cantilever, tests are conducted on various substrates. Nanoindentation is demonstrated on PDMS, hydrogel and endothelial cells to determine the Young’s modulus of these materials. Fluid force microscopy is showcased by examining prostate cancer cells (PCA-3), removing the cells from the substrate while measuring the adhesion forces. The imaging capabilities of the cantilever were also demonstrated by generating a height map and a Young’s modulus map through quantitative imaging of a hydrogel spheroid. This research shows that combining the properties of nanoindentation and FluidFM cantilevers into a single cantilever is possible. Integrating these functionalities into a single cantilever makes doing more mechanical measurements on a single cell possible.

Life at low-Reynolds numbers regime is intriguing. Single motile bacteria are known to exhibit erratic behaviour; they swim in what is known as a random walk, alternating between periods of swimming straight and abrupt moments of re-orientation. Yet in dense populations, cells of E.coli have been reported to exhibit weak synchronization and self-organize into collective oscillatory motion patterns. However, the origin of this rhythmic behaviour remains largely unknown. Here, we present a method of inducing self-sustained oscillations over minute timescales in single E.coli cells by trapping them in circular microcavities. By engineering the size of these microwells, we show that the velocity of single E.coli can be tuned between speeds ranging from a few to 20 um/s. Furthermore, we show that by connecting the microwells via on-chip channels, E.coli tend to coordinate their motion through hydrodynamic interaction and exhibit collective dynamics. Using analytical modeling, we extract the coupling strength and design the channels to mediate synchronized oscillation between two bacterial oscillators. Our work not only advances our understanding of the collective dynamics of swarming bacteria but also provides the first evidence for single-cell bacterial oscillators, paving the way to using micro-organism-inspired oscillations in applications as varied as antibiotic screening, scientific computing and micro-swimmers.

A stage heater for inverted optical microscopy was developed as an add-on to TU Delft portable integrated microfluidic platform. The platform was modified to gain additional functionality and portability. The stage heater was designed to work with custom PDMS microfluidic chips and commercial polymer chips which highlights the adaptability of the setup. The on-off temperature control was evaluated via an external thermocouple sensor, and the standard deviation of temperature in the cell chamber did not exceed 0.3 °C. An intermittent flow mode (flow for 1 minute at 10 µl/min, pause for 10 minutes) was introduced to match the requirements of an experiment involving T-cell and tumour spheroid interaction. The stage heater was deemed compatible with fluorescent and transmission imaging modes for up to 20x magnifications when equipped with a PET ITO-coated bottom heater with a window underneath the cell chamber. An increase in T-cell activity was observed with enabled heating. The process of T-cells attacking a spheroid via a time series of images was captured.

The Nobel Prize in Chemistry in 2017 went to the development of cryo-electron microscopy, which contributed to the discovery of new cells and viruses, the diagnosis of unknown diseases, the mapping of human genomes and the manufacturing of semiconductors. Cryo Correlative light and electron microscopy (Cryo-CLEM), is the combination of using fluorescence microscopy and cryo-electron microscopy to image cryo-immobilized bio-samples. These samples (at a temperature lower than −165ᵒC), require critical conditions in preparation and preservation to prevent contamination and heating which have a negative influence on the imaging results. In the current sample transfer workflow, almost 90% of the samples transferred end up being wasted due to the unideal protection and transfer gap. Therefore, an integrated high-vacuum sample transfer system which fits the interfaces of CLEM devices and actively protects the samples from heating and contamination in transfer has been designed to conquer the problems, ensure better imaging results, and increase the process yield. COMSOL simulations on its thermal and mechanical behaviors have been carried out to theoretically verify and iterate the design. The new transfer system provides a cheaper, faster, easier, more contamination-free, more temperature-stable, more user-friendly workflow that can increase the yield of sample transfer from 10% to 90%.

Microvalves are important flow-control devices in many standalone and integrated microfluidic applications. PDMS-based (Polydimethylsiloxane) pneumatic microvalves are the most commonly used type for research purposes, but they require large peripheral connections and cannot be used for controlling gases due to the high gas permeability of PDMS. There are many alternatives found in the literature that use Si-based microvalves, but variants that can throttle even moderate pressures (1 bar) tend to be bulky (cm-range), have a complex fabrication process, or consume high power. This thesis details the development of a low-power, normally-open piezoelectric microvalve to control flows with a maximum driving pressure of 1 bar, but also retain a small effective form-factor of 5mm x 5mm x 1.8mm. A novel combination of rapid-prototyping methods like stereolithography and laser-cutting was used to realize this device. The maximum displacement of the fabricated microactuator was measured to be 8.5 μm at 150V. The fabricated microvalve has a flow-range of 0 - 90 μL/min - water at 1 bar inlet pressure. When fully closed, a leakage of 0.8% open-flow was observed with a power-consumption of 37.5 μW. A flow resolution of 0.2 μL/min was measured at 0.5 bar pressure.

Any resonance based sensing method such as AFM or mass sensing using microfluidic cantilevers require high frequency stability. For mass measurement, a stable frequency allows for a lower mass resolution. One of the most commonly used methods to actuate these resonators is using piezoacoustics. A major downside of this method is the presence of spurious resonances, which corrugate the frequency response and can potentially degrade mass sensitivity. One way get rid of these spurious peaks is by
actuating photothermally (using laser light). This thesis is focused around designing and building a photothermal AFM to explore this. Additionally, some experiments are performed comparing piezoacoustic actuation to photothermal actuation in terms of the aforementioned frequency stability and
spurious peaks.

Microvalves are useful components for several microfluidic applications in which they control the fluid flow in a microfluidic system. Most microvalves to date are made by using silicon micro-machining, which is a complex manufacturing process, or soft lithography using Polydimethylsiloxane (PDMS) which has a high gas permeability. Next to that most microvalves in literature have small actuation forces resulting in small pressure ranges and large leakages at low pressure levels. In this paper, a normally open microvalve which is fabricated by only using 3D printing techniques with a bio-compatible resin is presented, making it more easy and accessible to manufacture. The novelty is the integrated micro-channels, membrane and microfluidic connections in a single 3D printed piece. The utilized actuator is a commercially available piezo stack, which has a displacement of 34 µm at 150V. Due to its large actuation force the microvalve can modulate fluids from -600 to 600 mbar, with measured flow-rate levels between 0-90 µl/min and projected flow-rate levels between 0-410 µl/min. In fully closed state the leakage-rate of the microvalve is 1.67 µl/min at 600 mbar, with a static power consumption of 442.5 mW. Subsequently it is shown that after using higher clamping torques (> 0.7 Nm) the microvalve can operate leakage free up to 1.5 bar. Additionally a 3-to-1 fluid selector is designed using three microvalves, which can be integrated into a portable microfluidic platform for Organ-on-Chip (OoC) applications.

Microfluidics has changed the way we think about laboratory experimental design. With the use of lab-on-chip devices, we are capable of carrying out experiments that include several functions on a single chip. Despite a lot of progress in the miniaturization of these devices, the peripheral systems which control the microfluidic functionalities like valves and pumps, remain bulky, making the microfluidic devices less portable. Conducting polymers are potential candidates that show promise to solve this issue and make the microfluidic devices portable. They are a class of polymer materials with intrinsic conductive properties and the ability to be formed and deformed at a low applied electric potential.
This thesis presents the different aspects of the conceptualisation and creation of the actuator for an all polymer conducting polymer microfluidic valve. The proposed system uses the widely studied multi-layer bending beam actuator, commonly used as an artificial muscle or soft actuator. The actuation of the all polymer system is the result of the different expansion rates during an electrochemical reaction.
The system consist of three polymer layers. The first layer is the flexible base layer that also functions as a fluid barrier in the microfluidic system. The second layer is the electrode material that is used as an electrode in both the fabrication and actuation of the expanding layer. The final layer is the electrochemically polymerized layer of expanding conducting polymer.
The all polymer actuator can eventually form the basis for new opportunities regarding the miniaturisation and commercialisation of Lab on Chip devices