The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 30, 1996
Filed:
Dec. 09, 1994
Donald J McDowell, Riverside, IL (US);
Force Imaging Technologies, Inc., Chicago, IL (US);
Abstract
An improved carbon-free force sensitive ink for a force sensor. The ink when deposited and dried can function at temperatures of up to 350.degree. F. and pressures of up to 10,000 psi. The preferred ink includes a thermoplastic polyimide binder, conductive particles, intrinsically semi-conductive particles, and dielectric particles, all of an average particle size of 1.0 micron or less. The preferred semi-conductive particles are molybdenum disulfide, ferric and ferrous oxide particles. The preferred conductive particles are conductive metal oxide compounds that deviate from stoichiometry based on an oxygen value of two, such as conductive tin oxide, Fe.sub.3 O.sub.4 iron oxide, and mixtures of them. The preferred dielectric particles are silica. The binder is present in an amount of 20 to 80% by volume. The sensor and a method of making the sensor are also disclosed.