Electronic nerve agent detector

• US 4,549,427 A
• Filed: 09/19/1983
• Issued: 10/29/1985
• Est. Priority Date: 09/19/1983
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Original Assignee: United States Of America As Represented By The Secretary Of The Air Force
• Inventors: Kolesar, Edward S. Jr.
• Primary Examiner(s): Lacey, David L.
• Assistant Examiner(s): Gzybowski, Michael S.
• Application Number:
  US06/533,331
• Time in Patent Office: 771 Days
• Field of Search: 73/23, 422/83, 422/88, 422/90, 422/98, 436/104, 436/902
• US Class Current: 73/24.01
• CPC Class Codes: G01N 2291/0256 Adsorption, desorption, surface mass change, e.g. on biosensors
• CPC Class Codes: G01N 29/036 by measuring frequency or resonance of acoustic waves
• CPC Class Codes: Y10T 436/163333 Organic [e.g., chemical warfare agents, insecticides, etc.]

Abstract

A personal field chemical warfare nerve agent detector has therein a transducer having two micromechanical cantilever oscillators. One of the cantilever oscillators has deposited, as an end-mass, a chemically selective substance on the cantilever. The nerve agent if present causes the natural resonant frequency to change. The changed resonant frequency is compared to a reference resonant frequency of the other cantilever oscillator without an end-mass. The amount of frequency change indicates the presence of a chemical nerve agent.

Claims

1. A chemical warfare nerve agent detector comprising:

a container having a cover and a case, said container having therein input and output air ports for circulating air through a detector section, an alarm port, an indicator display, an electronics section comprising electronic means, a power section, and said container having attaching means whereby said detector can be worn by a person;

at least one transducer mounted within said detector, said at least one transducer having an active cantilever oscillator and a reference cantilever oscillator, each of said at least one transducers having cantilevers essentially similarly shaped so that their natural resonant frequencies are closely matched, said cantilevers being electrically connected to said electronic means for detecting and measuring their oscillation frequencies, said cantilevers being mounted over a rectangular shaped well, the sides of said well comprising an insulating layer, the bottom of said well comprising a highly doped layer of semiconducter material, said highly doped layer being electrically connected to said electronic means, said highly doped layer being deposited on a silicon substrate that is mounted in said detector section, said active cantilever oscillator being chemically absorptive to a chemical agent by absorbing said chemical agent on a chemically selective substance attached to said active cantilever and said active cantilever being composed of metallic material, said reference cantilever oscillator having a reference cantilever being composed of metallic material, said chemically selective substance being a chemical composition selected from the group consisting of;

(1) XAD-4-Cu²⁺ -diamine;

(2) Cu (Butyrate)₂. Ethylenediamine;

(3) PVBC - Triethylenetetraamine - Cu²⁺ - Chloride;

(4) PVBC - Tetramethylethylenediamine - Cu²⁺ - Chloride;

(5) PVP - Tetramethylenediamine - Cu²⁺ - Chloride;

(6) PVP - Triethylenetetraamine - Cu²⁺ - Chloride; and

(7) PVP - 2, 2'"'"'- Bipyridine - Cu²⁺ - Chloride;

an air pump for causing an air flow through said detector section and over said at least one transducer in said detector section; and

said electronic means further comprising means for detecting the absorption of said chemical agent on said active cantilever wherein the frequency of said active cantilever is compared to the frequency of said reference cantilever, said electronic means measuring the amount of said chemical agent absorbed on the active cantilever by comparing the differences in frequencies between said active cantilever oscillator and said reference cantilever oscillator, said electronic means mounted in said electronic section, and electrically connected to said transducer, an alarm, and said indicator display and batteries for supplying electric power, said batteries being removably mounted in said power section.