Patent · US Active

MEMS fluid sensor

US8356885B2 · kind B2 · utility

4Cited by

18References

4Claims

0Family size

Assignee

Zamtec Ltd · IE

Inventors

Kia Silverbrook · Sydney, AU
Gregory John McAvoy · Sydney, AU
Angus John North · Sydney, AU
Samuel George Mallinson · Sydney, AU
Mehdi Azimi · Sydney, AU

Key dates

Filing date	Jan 5, 2010
Grant date	Jan 22, 2013
Priority date	—
Expiry date	Oct 22, 2030

Classification

Technology area (CPC B)Performing Operations; Transporting
CPC primaryB41J2202/20
WIPO fieldTextile and paper machines
WIPO sectorMechanical engineering

Abstract

A fluid sensor for detecting fluid in a chamber, has a MEMS sensing element of conductive material with a resistance that is a function of temperature, and electrical contacts for connection to an electrical power source for heating the sensing element with an electrical signal, so that control circuitry can measure the current passing through the sensing element during heating of the sensing element; and determine the temperature of the sensing element from the known applied voltage, the measured current and the known relationship between the current, resistance and temperature. As the temperature of the element will be greater if it is in the presence of gas rather than liquid, the sensor determines if there is liquid or gas in the chamber. This is particularly useful to detect if the chambers of an inkjet printhead are primed with ink.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.