Microchannel forming method and nanotipped dispensing device having a microchannel
A method of forming a microchannel as well as a thin film structure including same is made by forming a first thin film on a side of a substrate, forming a fugitive second thin film on the first thin film such that the second thin film defines a precursor of the elongated microchannel and a plurality of extensions connected to and extending transversely relative to the precursor along a length thereof A third thin film is formed on the first thin film and the fugitive second thin film such that the second thin film resides between the first thin film and the third thin film. A respective access site is formed in a region of the third thin film residing on a respective extension and penetrating to the fugitive second thin film. The fugitive second thin film forming the precursor is selectively removed from between the first thin film and the third thin film using an etching medium introduced through the access sites, thereby forming the microchannel between the first thin film and the third thin film. The method preferably further includes forming a sealing layer on the third thin film in a manner to close off open access sites remaining after selective removal of the second thin film.
1. A thin film structure comprising: a pair of thin films forming a microchannel therebetween, said microchannel having a plurality of microchannel extensions that extend transversely therefrom along the length of the microchannel, an access site in one of the thin films, and a sealing material closing off the access site.
2. The structure of claim 1 wherein the sealing material comprises a sealing layer on one of the thin films.
3. The structure of claim 1 wherein the extensions of the microchannel contain material of a thin film formerly residing between the pair of thin films.
4. A microcantilever comprising: a pair of thin films forming an elongated cantilever having a microchannel along the length of the cantilever between the thin films, said microchannel having a plurality of microchannel extensions that extend transversely therefrom along the length of the cantilever, one of the thin films having a respective access site to a respective extension of the microchannel, and a sealing material closing off the access site.
5. The microcantilever of claim 4 further including a piezoelectric actuator layer on one of the thin films.
6. The microcantilever of claim 4 wherein the extensions of the microchannel contain material of a thin film formerly residing between the pair of thin films.
7. The microcantilever of claim 4 further including a microtip for dispensing material.
8. The microcantilever of claim 7 wherein the microtip includes an annular space formed about a pointed tip.
9. The microcantilever of claim 8 wherein the pointed tip comprises diamond.
10. The microcantilever of claim 8 wherein the pointed tip comprises silicon carbide.
11. The microcantilever of claim 7 further including a reservoir on an opposite side of the cantilever from the microtip.
12. The microcantilever of claim 11 wherein one of the thin films includes one or more openings at such a location that the one or more openings communicate with the reservoir.
13. The microcantilever of claim 4 which is formed to extend from a semiconductor chip substrate.