Flexible Polymer Actuator for Rapid Fluid Metering
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Solution Overview
Problem
Osmotic delivery systems face delays due to air pockets or voids that compress and delay fluid release, and struggle with delivering viscous pharmaceutical agents due to low osmotic pressure, limiting their practicality and effectiveness.
Innovation Solution
A flexible actuator material is used that can be compressed during assembly or filling, creating a preloaded pressure condition to prevent delays and increase pressure through protonated molecular repulsive forces, allowing for efficient delivery of fluids, and the actuator is designed with varying layers of density and porosity to enhance pressure generation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional osmotic delivery systems are used, then fluid delivery is achieved, but delays occur due to air pockets or voids that compress during pump startup
Solution Approach 1:
The actuator material is pre-compressed during assembly or filling to create a preloaded pressure condition. This preliminary compression eliminates air pockets and voids before fluid delivery begins, ensuring immediate fluid expulsion without startup delays when the fluid tubing restrictions are removed.
2Force
If traditional osmotic pumps are used, then fluid delivery is achieved, but osmotic pressure is too low to deliver viscous pharmaceutical agents
Solution Approach 1:
The actuator material utilizes protonated molecular repulsive forces that occur upon hydration to generate pressures exceeding 50 psi per gram of actuator material. This chemical parameter change (protonation) creates strong repulsive forces that dramatically increase delivery pressure, enabling efficient delivery of viscous pharmaceutical agents.
3Strength
If rigid materials are used for the device structure, then structural strength is maintained, but patient comfort and package configuration are reduced
Solution Approach 1:
The device is constructed with flexible materials for the actuator and housing. The flexible actuator material provides both structural integrity and comfort for patient wear, while the flexible housing allows desirable package configurations. The flexibility of these materials enhances patient comfort without compromising the device's ability to generate and contain pressure.
4Shape
If polymer actuator material is cast into geometric shapes or ground into powder, then structural form is achieved, but diffusion is slowed and swelling size is decreased
Solution Approach 1:
The actuator material is provided as a flexible membrane or sheet with non-uniform local properties. This local quality configuration maintains structural form while preserving rapid hydration diffusion capabilities, as the membrane structure allows hydrating solution to penetrate more effectively than cast or ground powder forms.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The flexible actuator material ensures immediate fluid delivery by relaxing and absorbing hydrating fluids, and generates pressures sufficient to deliver viscous agents effectively, overcoming the limitations of traditional osmotic pumps.
Implementation Method 1
osmotic delivery systems operate by absorbing fluid from the outside environment and releasing corresponding amounts of the beneficial agent
Implementation Method 2
the introduction of protonated molecular repulsive forces, that occur upon hydration of the flexible actuator material and can produce pressures in excess of 50 ponds per square inch per gram of actuator material
Data Source
AI summary
A wearable fluid metering device for delivering medication subcutaneously, intramuscularly or intravenously to a patient, includes a polymer actuator pump. The polymer actuator pump is flexible so it will conform to shape and yet can be used to rapidly displace a volume within a confined area. The actuator is much faster than prior art polymer actuator designs and can be actuated in multiple ways including introduction and hydration of the polymer matrix by a solution or the actuator can be actuated via pH change while it is in solution. The pH change can be made via electrical current such as that used in electro chemistry or the pH change can be made via a chemical change introduced to the actuator hydrating solution.