Using MEMS to Miniaturize Mobile Phones

securitas writes: "The NY Times has a feature on using microelectro-mechanical systems (MEMS) in cell phones to replace bulky passive components like the filters, resonators and duplexers that make up most of the size of today's phones. In theory, they say, you could have a cell phone in a ring on your finger. Besides making everyone seem like James Bond, a ring-phone would give new meaning to the phrase 'Talk to the hand.'"

Comments

Great....

[tfurrows]

So now we're going to have a bunch of yuppies talking to their fingers while they drive.

Does this mean people are going to get pulled over for talking on their cell (in areas where it's illegal), when all they were really doing was picking their nose?

What an injustice... what a travisty....

One Ring to Bind them?

[Matey-O]

Actually, One ring says I'm committed to my wife. The other Ring shows my commitment to technology!

Shameless plugs

[Doctor K]

I am working in the MEMs area these days. So here are some shameless plugs.

Here
is an general interest article from the group in which I work with some details oriented towards these types of mesoscopic MEMs.

Here
is a neat picture of a Mesoscopic MEMs device (an acceleratometer resting on top the middle part of the "8" in a 1998 penny.

And though my research at Berkeley wasn't MEMS oriented, Berkeley MEMS is pretty active. Here is a link to that.

As the article points out, MEMS are finding applications in cell phones because it is easy to make very small RF filters using inertial effects to provide inductive-like impedences. (In the past, the inductive like parts of a cell-phone filter would either be done with spiral inductors, which are unwieldly or via other microwave circuit voodoo.)

However, beyond cell phones is a grab bag of MEMs applications already at or beyond the prototype stage:
- Car air bag detectors (the above accelerometer)
- Laser gyroscopes
- Projection displays (pixel mirrors arrays)
- Optical fiber switches
- Medical applications (microfluidics, bio-chips, ...)
- Remote sensing (minaturized microphones, or in the future, smart dust)

Enjoy
Kevin

Re:Coltan

[Hal-9001]

For people like me who had no idea what coltan is, see this article. The short version is that columbite-tantalite (coltan) is an ore than can be refined into tantalum, which apparently is a very good dielectric for making capacitors. This means that it's not just in cell phones but probably in every electronic device you own.

The controversy over coltan and the Congo seems to revolve around two issues. One is that Congo's neighbors seem to be exploiting its coltan resources, i.e. smuggling coltan and exporting it as their own product. Another is the environmental impact, since illegal mining operations probably care as much about the environmental impact they have as they do about the law.

All of this so far is off-topic, but if rf MEMs could replace capacitive filters and resonators, it could help reduce the demand for coltan. This feeble attempt to be on-topic is purely speculative, though, as I am not a wireless engineer and the NYT article lacks details about the materials being used in these devices.