Patent ID: 7841702

Claim:
A heater stack for a micro-fluid ejection device comprising: first strata configured to support and form a fluid heater element responsive to repetitive electrical activation and deactivation to produce repetitive cycles of fluid ejection from said device; and second strata overlying said first strata to provide protection of said fluid heater element from adverse effects of said repetitive cycles of fluid ejection, each cycle involving alternating periods of heat-up and cool-down of said fluid heater element; wherein said first strata includes a substrate a heater substrata overlying said substrate, and a sacrificial layer of material deposed between said substrate and said heater substrata and processed so as to provide a decoupled relationship at least between said fluid heater element and said substrate which, during the heat-up period of a respective one of said cycles of fluid ejection, results in said fluid heater element buckling away from and out of physical contact with said substrate due to thermal expansion of said fluid heater element in response to the electrical activation thereof enabling said fluid heater element to transfer heat energy for producing fluid ejection into the fluid substantially without transferring the heat energy into said substrate whereas said decoupled relationship, during the next following cool-down period of the respective one of said cycles of fluid ejection, results in said fluid heater element de-buckling back toward and into physical contact with said substrate due to thermal contraction of said fluid heater element in response to the electrical deactivation thereof enabling said fluid heater element to transfer residual heat energy to said substrate and prepare for the following heat-up period of the next respective one of said cycles of fluid ejection.