David R Weir

US Patent:

20130055709, Mar 7, 2013

Filed:

Aug 16, 2012

Appl. No.:

13/587150

Inventors:

Clint T. Apland - Elkridge MD, US
David R. Weir - Hanover PA, US
David F. Persons - Columbia MD, US
Michael T. Marley - Elkridge MD, US

Assignee:

THE JOHNS HOPKINS UNIVERSITY - Baltimore MD

International Classification:

F03G 7/06

US Classification:

60528, 60527, 60529

Abstract:

An actuator includes a capturing part, a retained part and a heating element which applies heat to the retained part or the capturing part responsive to selective application of power to the at least one heating element. The capturing part attaches to a first object and has a first coefficient of thermal expansion. The retained part attaches to a second object and has a second coefficient of thermal expansion. The retained part is insertable into the capturing part in a first state of the actuator. The retained part is held in contact with the capturing part via an interference fit to hold the first and second objects proximate to each other in a second state. The retained part is ejected from the capturing part in a third state. Applying heat via the heating element causes a transition between the second and the first or third states of the actuator.