The following operators can be used to better focus your queries.
( ) , AND, OR, NOT, W/#
? single char wildcard, not at start
* multi char wildcard, not at start
(Cat? OR feline) AND NOT dog?
Cat? W/5 behavior
(Cat? OR feline) AND traits
Cat AND charact*
This guide provides a more detailed description of the syntax that is supported along with examples.
This search box also supports the look-up of an IP.com Digital Signature (also referred to as Fingerprint); enter the 72-, 48-, or 32-character code to retrieve details of the associated file or submission.
Concept Search - What can I type?
For a concept search, you can enter phrases, sentences, or full paragraphs in English. For example, copy and paste the abstract of a patent application or paragraphs from an article.
Concept search eliminates the need for complex Boolean syntax to inform retrieval. Our Semantic Gist engine uses advanced cognitive semantic analysis to extract the meaning of data. This reduces the chances of missing valuable information, that may result from traditional keyword searching.
An acoustic transducer can be produced in crystalline silicon by electrically introducing a strain into the crystal.
English (United States)
This text was extracted from a PDF file.
This is the abbreviated version, containing approximately
74% of the total text.
Page 1 of 1
Silicon Ultrasonic Transducer
An acoustic transducer can be produced in crystalline silicon by electrically
introducing a strain into the crystal.
It is well known that in inversion layers on the surface of a multivalley
semiconductor such as silicon, the energies of the various valleys are split.
Electrons preferentially occupy the lowest energy valley. In such a circumstance,
the crystal can lower its energy by assuming a strain that lowers the energy of
the valleys occupied by electrons. By modulating the number of electrons in the
inversion layer by the field effect, the strain can be periodically varied and thus
serve as a radiator of acoustic energy.
Thus specifically, the proposed transducer applied to surface waves would
consist of a number of stripes parallel to one another and perpendicular to the
intended direction of propagation on a (001) surface of silicon. The stripes would
be MOS structures; in other words, a metal or polysilicon layer separated from
the silicon by a thin layer of oxide. A periodically varying potential would be
applied between the silicon and the metal stripes. The number of electrons in the
inversion layer would vary with the potential, producing an oscillating strain and
exciting elastic waves.
The magnitude of the strain produced by the effect can be very
roughly estimated as follows. The energy cost of straining the
and the energy gained by lowering the energy of the valleys is: