Non-viscoelastic castable elastomers are replacing the polyacrylate VHB films in new generations of dielectric elastomer actuators (DEAs) to achieve fast and reliable actuation. We introduce optimum prestretch conditions enhance electromechanical behavior DEAs resulting large actuation strain. For actuator which thickness is selected independent prestretch, uniaxial mode offers highest strain transverse direction compared biaxial pure shear. experimentally demonstrate that miniaturization...

Cells regulate their behavior in response to mechanical strains. Cell cultures study mechanotransuction are typically cm2 area, far too large monitor single cell response. We have developed an array of dielectric elastomer microactuators as a tool mechanotransduction individual cells. The consists 72 100 µm × 200 electroactive polymer actuators which expand uniaxially when voltage is applied. Single cells will be attached on each actuator periodic device fabricated by patterning compliant...

High throughput heterogeneous immunoassays that screen antigen-specific antibody secreting cells are essential to accelerate monoclonal discovery for therapeutic applications. Here, we introduce a single cell immunoassay based on alginate microparticles as permeable culture chambers. Using microfluidic device, encapsulated in 35–40 μm diameter microbeads. We functionalized the capture secreted antibodies inside microparticles, enabling analysis and preventing cross-talk between neighboring...

Biocompatible microparticles are valuable tools in biomedical research for applications such as drug delivery, cell transplantation therapy, and analytical assays. However, their translation into clinical the pharmaceutical industry has been slow due to lack of techniques that can produce with controlled physicochemical properties at high throughput. We introduce a robust microfluidic platform production relatively homogeneous microdroplets generation frequency up 3.1 MHz, which is about...

Conventional robots are typically actuated by hard actuators, while biological entities consist mostly of soft muscles. Being imparts a functionality compliance, thereby greatly enhancing the range actuation and degrees freedom. Here, we demonstrate electromechanically-active polymer capable an electrically-induced linear strain beyond 500% that is continuously tunable voltage. Previous experiments on same material have demonstrated harnessing bypassing electromechanical instability,...

Therapeutics based on ribonucleic acid (RNA), particularly messenger RNA (mRNA) therapies, are transforming the treatment landscape for various diseases, including infectious diseases and cancer. A key challenge in widespread adoption of these therapies is ensuring long-term stability mRNA lipid nanoparticles (LNPs), which essential effective delivery. In this study, we examined mRNA-encapsulated LNPs stored single-use (SU) bags, a cost-effective scalable solution pharmaceutical storage. Our...

To better understanding fluid dynamics within microfluidic channels, herein, we present an accurate experimental approach for studying the of rapid processes devices using bright-field microscopy with white light illumination.

Abstract Dynamic behaviour of a slider–crank mechanism associated with smart flexible connecting rod is investigated. Effect various mechanisms' parameters including crank length, flexibility the and slider's mass on dynamic studied. Two control schemes are proposed for elastodynamic vibration suppression also obtaining constant angular velocity crank. The first scheme based feedback linearization approach second one sliding mode controller. input signals applied by an electric motor located...

Mechanical stimuli are critical for the development and maintenance of most tissues such as muscles, cartilage, bones blood vessels. The commercially available cell culture systems replicating in vivo environment typically based on simple membrane cell-stretching equipment, which can only measure average response large colonies cells over areas greater than one cm². We present here conceptual design complete fabrication process an array 128 Electro-Active Polymer (EAP)...

Silicone based dielectric elastomer actuators are preferred for reliable and fast actuation due to their negligible viscoelastic behavior. However, it is more challenging achieve large deformation using this class of polymers compared the traditionally used VHB films. In paper, we present theoretical guidelines improving strain silicone actuators. The electromechanical behavior two different silicones demonstrated that softest not necessarily best choice deformation. Lastly, have...

Bioprocess optimization towards higher productivity and better quality control relies on real-time process monitoring tools to measure culture parameters. Cell concentration viability are among the most important parameters be monitored during bioreactor operations that typically determined using optical methods an extracted sample. In this paper, we have developed online non-invasive sensor cell based Doppler ultrasound. An ultrasound transducer is mounted outside vessel emits a high...

Dielectric Elastomer Actuators (DEA) are compliant devices capable of generating large percentage strains with sub-second response times. Miniaturizing DEAs is challenging principally because the need for μm-scale electrodes. Employing low-energy gold-ion implantation into a 30 μm thick membrane Polydimethylsiloxane (PDMS), we have patterned 100 wide electrodes and fabricated arrays x reaching up to 80% in-plane strain at 4 kV. The actuators designed be used stretch single biological cells...

We present the design, fabrication process and characterization of multilayer miniaturized polydimethylsiloxane (PDMS)-based dielectric elastomer diaphragm actuators. The conductive stretchable electrodes are obtained by lowenergy metal ion implantation. To increase force, decrease required voltage, avoid breakdown, we here a technique to fabricate devices with embedded complex shapes. By implanting on partially cured PDMS film, then casting it next layer PDMS, is possible have compliant...

Keywords: dielectric elastomer actuator ; microactuators low energy ion-implantation cell stretcher high throughput theoretical analysis These Ecole polytechnique federale de Lausanne EPFL, n° 5697 (2013)Programme doctoral Microsystemes et MicroelectroniqueFaculte des sciences techniques l'ingenieurInstitut microtechniqueLaboratoire microsystemes pour les technologies spatialesJury: P.-A. Farine (president), F. Carpi, I. Graz, Ph. Renaud Public defense: 2013-6-6 Reference...

Biological cells regulate their biochemical behavior in response to mechanical stress present organism. Most of the available cell cultures designed study effect stimuli on are cm² area, far too large monitor single or have a very low throughput. We developed two sets high throughput stretcher devices based dielectric elastomer microactuators stretch groups individual with various strain levels experiment. The first device consists an array 100 μm x 200 actuators...

We introduce a novel platform for cell line optimization mAb production using digital microfluidics. The enables testing of culture samples in 6–8 μL droplets with semi-automated viability, media pH, and antibody assays.

Herein, an accurate approximate analytical solution for oscillation of nonlinear systems modelled by a mass attached to stretched elastic wire is derived using the homotopy analysis method and Pade technique. Approximate expressions frequency displacement with respect time are obtained. Comparison between presented results numerical solutions shows that first-order approximation technique leads results.