Droplet microactuator system

The present invention relates to a droplet microactuator system. According to one embodiment, the droplet microactuator system includes: (a) a droplet microactuator configured to conduct droplet operations; (b) a magnetic field source arranged to immobilize magnetically responsive beads in a droplet during droplet operations; (c) a sensor configured in a sensing relationship with the droplet microactuator, such that the sensor is capable of sensing a signal from and/or a property of one or more droplets on the droplet microactuator; and (d) one or more processors electronically coupled to the droplet microactuator and programmed to control electrowetting-mediated droplet operations on the droplet actuator and process electronic signals from the sensor

Piezoresistor-Embedded Multifunctional Magnetic Microactuators for Implantable Self-Clearing Catheter

Indwelling catheters are used widely in medicine to treat various chronic medical conditions. However, chronic implantation of catheters often leads to a premature failure due to biofilm accumulation. Previously we reported on the development of a self-clearing catheter by integrating polymer-based microscale magnetic actuators. The microactuator provides an active anti-biofouling mechanism to disrupt and remove adsorbed biofilm on demand using an externally applied stimulus. During an in vivo evaluation of self-clearing catheter, we realized that it is important to periodically monitor the performance of implanted microactuators. Here we integrate gold-based piezoresistive strain-gauge on our magnetic microactuators to directly monitor the device deflection with good sensitivity (0.035%/Deg) and linear range (±30°). With the integrated strain-gauge, we demonstrate the multi-functional capabilities of our magnetic microactuators that enable device alignment, flow-rate measurement, and obstruction detection and removal towards the development of chronically implantable self-clearing smart catheter

Micromachined capacitive long-range displacement sensor

First measurement results are presented for a surface-micromachined long-range (50– 100 μm) periodic capacitive position sensor. The sensor consists of two periodic geometries (period = 10 μm) sliding along each other with minimum spacing of about 1.5 μm. The relative displacement between the two, results in a periodic change in capacitance. An electrostatic comb-drive actuator is employed to generate displacements. Measured maximum capacitance change ΔC=0.72 fF corresponds to simulation results but needs better shielding from external noise sources. The results show this sensorconcept can potentially lead towards long-range nano-positioning control of microactuator systems

Design and Simulation of a Novel Magnetic Microactuator for Microrobots in Lab-On-a-Chip Applications

This article presents the design of a magnetic microactuator comprising soft magnetic material blocks and flexible beams. The modular layout of the proposed microactuator promotes scalability towards different microrobotic applications using low magnetic fields.  The presented microactuator consists of three soft magnetic material (Ni-Fe 4750) blocks connected together via two Polydimethylsiloxane (PDMS) semi-circular beams. A detailed design approach is highlighted giving considerations toward compactness, range of motion and force characteristics of the actuator. The actuator displacement and force characteristics are approximately linear in the magnetic field strength range of 80-160 kA/m. It can achieve maximum displacements of 111.6 µm (at 160 kA/m) during extension and 10.7 µm (at 80 kA/m) during contraction under no-load condition. The maximum force output of the microactuator, computed through a contact simulation, was 404.3 nN at a magnetic field strength of 160 kA/m. The microactuator achieved stroke angles up to 18.4 in a study where the microactuator was integrated with a swimming microrobot executing rowing motion using an artificial appendage, providing insight into the capabilities of actuating untethered microrobots

Capacitive long-range position sensor for microactuators

Design, fabrication and measurements for a capacitive long-range position sensor for microactuators are presented. The sensor consists of two periodic geometries (period ≈ 8-16 µm) on resp. a slider and a sense-structure with minimal gap-distance of ~ 1 µm. A relative displacement between the two results in a periodic change in capacitance. In open-loop operation the change in capacitance vs. slider displacement is measured using synchronous detection. Adjusting the minimal gap-distance with additional sense-actuators increases the capacitance. In closed-loop operation the position of the sense-structure is controlled to keep the sensor-capacitance at a larger constant value. Our results indicate that the position precision is increased to 18 nm in closed-loop operation compared to 70 nm in open-loop operation

Systems, methods, and products for graphically illustrating and controlling a droplet actuator

Systems for controlling a droplet microactuator are provided. According to one embodiment, a system is provided and includes a controller, a droplet microactuator electronically coupled to the controller, and a display device displaying a user interface electronically coupled to the controller, wherein the system is programmed and configured to permit a user to effect a droplet manipulation by interacting with the user interface. According to another embodiment, a system is provided and includes a processor, a display device electronically coupled to the processor, and software loaded and/or stored in a storage device electronically coupled to the controller, a memory device electronically coupled to the controller, and/or the controller and programmed to display an interactive map of a droplet microactuator. According to yet another embodiment, a system is provided and includes a controller, a droplet microactuator electronically coupled to the controller, a display device displaying a user interface electronically coupled to the controller, and software for executing a protocol loaded and/or stored in a storage device electronically coupled to the controller, a memory device electronically coupled to the controller, and/or the controller