Direct assembly process for fabrication of ionomeric polymer devices

Abstract

Ionomeric polymer sensors, actuators, and transducers and methods for fabricating them are disclosed. One embodiment of the sensors, actuators, and transducers possess a high surface area electrode layer that is applied by hot pressing and a highly conductive surface layer. Another embodiment of these sensors, actuators, and transducers possess a high surface area electrode layer that is penetrated by electronically conductive nanowires. Methods for fabricating these sensors, actuators, and transducers are disclosed. These methods involve the formation of the high surface area layer from a liquid mixture that contains ionomeric polymer, electronically conductive particles, and possibly diluent. This mixture is formed into layers either directly on an ionomeric polymer, on a separate transfer decal, or on an electronically conductive layer. This electronically conductive layer may also include an array of nanowires. These electrode layers are then attached to an ionomeric polymer membrane by hot pressing. The ionomeric polymer membrane may be swollen with a diluent either prior to the hot pressing or after the hot pressing step. Also, the ionomeric polymer membrane may be formed by casting from a liquid mixture containing ionomeric polymer and diluent.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims priority to U.S. Provisional Patent Application Ser. No. 60 / 661,015 filed Mar. 14, 2005, and the complete contents of this application are herein incorporated by reference.STATEMENT OF GOVERNMENT INTEREST [0002] This invention was made with government support under Contract Number DAAD19-02-1-0275 awarded by the U.S. Army Research Laboratory and the U.S. Army Research Office. The Government has certain rights in the invention.DESCRIPTION Background of the Invention [0003] 1. Field of the Invention [0004] The present invention generally relates to ionic polymer transducers, sensors and actuators. [0005] 2. Description of the Prior Art [0006] Ionomeric polymer membranes are materials that behave as solid-state electrolytes, making them useful in a variety of applications, including fuel cells, water electrolyzers, transducers, actuators and sensors. Ionomeric polymer membrane transducers have existed in their curre...

AI Technical Summary

Benefits of technology

[0018] It is therefore an object of the present invention to provide a new fabrication technique for ionomeric transducers, actuators and / or sensors using a more precise, more controllable, and less expensive method. The transducers of the invention exhibit superior transduction performance, including larger strain generation. This method allows the area of the ionomer / electrode interface to be maximized and the geometry and morphology of the electrode and the ionomer / electrode interface to be well-controlled. Additionally, this invention includes a technique to ensure that the electrical conductivity of the electrodes in the plane of the transducers is high.

Problems solved by technology

However, these actuators are unable to operate in air without a means of supplying continuous hydration due to drying of the device by evaporation of the water.

However, the authors make no mention of the diluent to be used in the transducers and it is left to the reader to assume that the final device will be swollen with water.

Based on these understandings, the performance of ionomeric polymer transducers is fundamentally limited by the volume of charge that can be accumulated at the ionomer / electrode interface and the rate with which this charge can be accumulated.

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