Temperature responsive systems

• US 8,172,458 B2
• Filed: 09/29/2008
• Issued: 05/08/2012
• Est. Priority Date: 03/23/2001
• Status: Active Grant

• Current Assignee: Dennis N. Petrakis
• Original Assignee: Dennis N. Petrakis
• Inventors: Petrakis, Dennis N.
• Primary Examiner(s): Verbitsky, Gail
• Application Number:
  US12/285,128
• Publication Number:
  US 20090041085A1
• Time in Patent Office: 1,317 Days
• Field of Search: 374/4, 374/5, 374/55, 374/57, 374/100, 374/187, 374205-207, 374101-109, 374/43, 374/44, 374/45, 374/46, 374/47, 374/48, 374/49, 374/50, 374/52, 374/160, 374/141, 222/54, 429/62, 403/381, 600/118, 605/27, 605/28, 605/29, 604/890.1, 604/95.01, 604/95.03, 604/95.04, 604/510, 604/528
• US Class Current: 374/101
• CPC Class Codes: A61M 2205/0266 Shape memory materials
• CPC Class Codes: A61M 31/002 Devices for releasing a drug at a continuous and controlled rate for a prolonged period of time artificial gland structures or devices A61F2/022; intra-uterine contraceptive devices A61F6/14; tampons for introducing into the vagina A61F13/20, A61L15/00; suppositories or bougies for intra-vaginal or intra-uterine application A61K9/02; physical forms of medicinal preparations for sustained or differential drug release A61K9/20, A61K9/50
• CPC Class Codes: G01K 5/483 using materials with a configuration memory, e.g. Ni-Ti alloys

Abstract

A shape memory material activated device of the present invention uses a shape memory material activator to create a path through a shell wall of the device. The path through the shell wall may release a substance contained in the shell or allow a substance to enter the shell. The path may be created by fracturing, puncturing, exploding, imploding, peeling, tearing, stretching, separating, debonding, abrading or otherwise opening the shell and, may be permanent or reversible. The substance may be released in one location while the device is stationary or along a path while it is traveling, self-powered by the shape memory material activator. In addition, the substance may be delivered to an object upon contact with its surface. The self powering abilities allow these devices to be used as substance delivery devices as well as actuators, transporters, and energy conversion systems with modular characteristics and growth potential. The devices may be armed, prior to the beginning of their service life, to be placed in a state of readiness to release their substances once the path is created. Prior to arming they may be maintained at any temperature, incapable of releasing their substances. The devices according to the present invention may be used as temperature sensors or warning devices, drug delivery devices, and the like.

Claims

1. A temperature activated device to provide actuation, comprising:

an activator made from a shape memory material, the shape memory material being deformable at a first temperature, then recovers its original, undeformed shape upon heating above a second, higher temperature, defining an active state of readiness of the activator, the shape memory material activator having an undeformed shape incapable of undergoing shape recovery and being normally unresponsive to temperature changes and defining a dormant state thereby maintaining the undeformed shape regardless of the temperature changes; and

means for deforming the activator in situ by only a single irreversible action, whereby the device is transformed from the dormant state to an active state of readiness, thereby the shape memory material activator is enabled to undergo shape recovery wherein the activator responds to temperature changes and the device becomes a functioning actuator.

2. A method for arming a temperature activated device, the method comprising the steps of:

providing an activator made from a shape memory material, wherein the shape memory material deforms at a first temperature, then recovers its original, undeformed shape upon heating above a second, higher temperature, defining an active state of readiness of the activator, the shape memory material activator having an undeformed shape incapable of undergoing shape recovery and being normally unresponsive to temperature changes and defining a dormant state thereby maintaining the undeformed shape regardless of the temperature changes; and

deforming the activator in situ by only a single irreversible action, whereby the device is transformed from the dormant state to an active state of readiness, thereby the shape memory material activator is enabled to undergo shape recovery wherein the activator responds to temperature changes.

3. An extended temperature responding shape memory material device, comprising:

an initially variably deformed shape memory material element having unequally deformed locations thereby responding to different shape recovery temperatures, wherein the non-uniformly deformed locations define least deformed locations and most deformed locations, wherein the shape memory material element undergoes non-uniform shape recovery within a predetermined extended temperature range beginning from the least deformed locations and proceeding to the most deformed locations with increasing temperature.