An implantable MEMS micropump system for drug delivery in small animals.

We present the first implantable drug delivery system for controlled timing and location of dosing in small animals. Current implantable drug delivery devices do not provide control over these factors nor are they feasible for implantation in research animals as small as mice. Our system utilizes an integrated electrolysis micropump, is refillable, has an inert drug reservoir for broad drug compatibility, and is capable of adjustment to the delivery regimen while implanted.

A Parylene Bellows Electrochemical Actuator.

We present the first electrochemical actuator with Parylene bellows for large-deflection operation. The bellows diaphragm was fabricated using a polyethylene-glycol-based sacrificial molding technique followed by coating in Parylene C. Bellows were mechanically characterized and integrated with a pair of interdigitated electrodes to form an electrochemical actuator that is suitable for low-power pumping of fluids.

Mini drug pump for ophthalmic use.

Purpose: To evaluate the feasibility of developing a novel mini drug pump for ophthalmic use.

Methods: Using principles of microelectromechanical systems engineering, a mini drug pump was fabricated. The pumping mechanism is based on electrolysis and the pump includes a drug refill port as well as a check valve to control drug delivery.

Mini drug pump for ophthalmic use.

Purpose: To evaluate the feasibility of developing a novel mini drug pump for ophthalmic use.

Methods: Using principles of microelectromechanical systems engineering, a mini drug pump was fabricated. The pumping mechanism is based on electrolysis, and the pump includes a drug refill port as well as a check valve to control drug delivery.

A low power, on demand electrothermal valve for wireless drug delivery applications.

We present a low power, on demand Parylene MEMS electrothermal valve. A novel Omega-shaped thermal resistive element requires low power (approximately mW) and enables rapid valve opening (approximately ms). Using both finite element analysis and valve opening experiments, a robust resistive element design for improved valve opening performance in water was obtained.

Implantable MEMS drug delivery pumps for small animal research.

Advanced devices capable of selective delivery of compounds to targeted tissues are lacking, especially in small animal research. Biomedical microelectromechanical systems (bioMEMS) are uniquely suited to this application through the combination of scalability and precise control of fluid handling. Polymer-based drug delivery components and pumps for acute and chronic delivery in small animals are discussed.

A Parylene MEMS Electrothermal Valve.

The first microelectromechanical-system normally closed electrothermal valve constructed using Parylene C is described, which enables both low power (in milliwatts) and rapid operation (in milliseconds). This low-power valve is well suited for applications in wirelessly controlled implantable drug-delivery systems. The simple design was analyzed using both theory and modeling and then characterized in benchtop experiments.

A passive MEMS drug delivery pump for treatment of ocular diseases.

An implantable manually-actuated drug delivery device, consisting of a refillable drug reservoir, flexible cannula, check valve, and suture tabs, was investigated as a new approach for delivering pharmaceuticals to treat chronic ocular diseases. Devices are fabricated by molding and bonding three structured layers of polydimethylsiloxane. A 30 gauge non-coring needle was used to refill the reservoir; this size maximized the number of repeated refills while minimizing damage to the reservoir.

A refillable microfabricated drug delivery device for treatment of ocular diseases.

An implantable manually-actuated microfabricated drug delivery device was demonstrated as a new approach for delivering therapeutic compounds to ocular tissue in acute in vitro, ex vivo, and in vivo studies.