Actuator is portable and can be used in high-temperature (over 500 C) environments by incorporating tungsten metal film and quartz window. Actuator can be triggered when it is not directly in laser beam path by utilizing fiber optics. It is advantageous for remotely switching ultra-high voltage systems

Murphy, A. J.

Yang, L. C.

English

NASA Technical Reports Server

1 
Body 
Q-Switch
September 1974	 B74-10166 
NASA TECH BRIEF 
NASA Pasadena Office 
NASA Tech Briefs announce new technology derived from the U.S space program. They are issued to encourage 
commercial application. Tech Briefs are available on a subscription basis from the National Technical Information 
Service, Springfield, Virginia 22151. Requests for individual copies or questions relating to the Tech Brief program may 
be directed to the Technology Utilization Office, NASA, Code KT, Washington, D.C. 20546. 
Laser-Actuated Mechanical Device
Stroke 
Limited by 
Length of 
Tact Rndv
HIM 
Laser-Actuated Mechanical Device 
The problem: 
Pyrotechnical devices are frequently used for the 
remote actuation of mechanisms located in inaccessible 
locations, i.e., environmental test chambers or on board 
spacecraft. This method of using explosives, however, 
has several disadvantages: 
a. To be triggered, pyrotechnical devices require un-
wieldy electrical connecting wires with a power 
supply. Should they be types that are triggered with 
radio signals, the signals may interfere with the 
operation of other electronic equipment in the 
vicinity. 
b. The end products of explosion, mixtures of solids 
and gases, often contaminate nearby equipment. 
c. The explosions can cause mechanical shocks to 
measuring instruments. 
d. Pyrotechnical devices are hazardous to handle and 
store.
The solution: 
A mechanical actuator operated by a Q-switched 
laser is a safer and a more convenient alternative. 
How it's done: 
The actuator shown in the figure contains an alumi-
num film approximately 100 rim thick which is vacuum 
deposited on a transparent disk of high optical trans-
parency and mechanical strength. A Q-switched ruby 
laser producing a 4.04 pulse of 0.02 .1z duration is 
directed at the metallic film. When the film vaporizes, 
the resultant high-intensity pressure pushes a piston to 
the limit (1 in. or 2.5 cm) of the test body and breaks 
a shearpin. 
The piston is 0.68 in. (1.72 cm) in diameter and 
weighs approximately 0.4 oz (11 g). The shearpin is a 
brass wire 0.031 in. (0.078 cm) in diameter and shears 
when subjected to a force of 65 lb (290 N). The actuator 
(continued overleaf) 
4
This document was prepared under the sponsorship of the National
	 Government assumes any liability resulting from the use of the 
Aeronautics and Space Administration. Neither the United States
	 information contained in this document, or warrants that such use 
Government nor any person acting on behalf of the United States
	
will be free from privately owned rights.
https://ntrs.nasa.gov/search.jsp?R=19740000166 2020-03-17T13:49:03+00:00Z
fr-
characteristics and dimensions can be modified to meet 
different performance requirements. 
The pressure pulse (as determined by using a quartz 
crystal gauge) has a peak pressure of 2x10 8 N/rn 2 and a 
duration of 2 Iz. The mass of the film is approximately 
0.05 mg as compared to an equivalent pyrotechnic 
device which contains 40 mg of powder. Thus the new 
actuator minimizes the contamination problem. The 
energy required to shear the pin is of the order of 
0.1 cal as compared to an equivalent pyrotechnic device 
which generates approximately. 100 cal. As a result, 
the shock problem is also greatly minimized. 
The actuator is portable and can be used in high. 
temperature (over 500° C) environments by incorpo-
rating a tungsten metal film and a quartz window. The 
actuator also can be triggered when it is not directly in 
the laser beam path by utilizing fiber optics. It is 
advantageous for remotely switching ultra-high voltage 
systems.
Notes: 
1. The actuator may be of interest to test engineers and 
to manufacturers of remote-control mechanical actu-
ators. 
Requests for further information may be directed to: 
Technology Utilization Officer 
NASA Pasadena Office 
4800 Oak Grove Drive 
Pasadena, California 91103 
Reference: TSP74-10166 
Patent status: 
This invention has been patented by NASA (U.S. 
Patent No. 3,798,896). Inquiries concerning nonex-
clusive or exclusive license for its commercial develop-
ment should be addressed to: 
Patent Counsel 
NASA Pasadena Office 
4800 Oak Grove Drive 
Pasadena, California 91103 
Source: Arthur J. Murphy and

Lien C. Yang of
Caltech/JPL
under contract to

NASA Pasadena Office
(NPO-13105)
. 
114-10166
	
Category O3,06,07


Laser-actuated mechanical device

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