Hi Ramji,

A very simple way of making a MEMS temperature sensor is using a metal
resistor. By measuring its resistance, you can calculate the temperature.
In general, its resistance at temperature T can be written as
R=Ro(1+alpha*(T-To)), where alpha is the Temperature coefficient of
resistance (TCR), and Ro the resistance at the temperature T. The following
website contains a good listing of temperature coefficients:
http://www.goodfellow.com/csp/active/gfMaterialTables.csp?type=00&prop=ELE
(Search for non-metals on
http://www.goodfellow.com/csp/active/gfMaterials.csp )

One reason why people use serpentine structures is to maximize the
resistance of the sensor relative to the contact resistances.

To be sure your resistor is measuring the temperature of the ambient air,
you might want to have it free-hanging, like a hotwire anemometer.

(Actually, nearly any MEMS sensor, in some way, can be used as a temperature
sensor.)

Good luck,

Sjoerd Haasl
Royal Institute of Technology
Stockholm, Sweden

>Message: 11
>Date: Sun, 21 Sep 2003 17:47:02 -0700 (PDT)
>From: ramji dhakal 
>Subject: [mems-talk] Temperature sensing in MEMS
>To: General MEMS discussion 
>Message-ID: <[email protected]>
>Content-Type: text/plain; charset=us-ascii
>
>Hi MEMS workers,
>
>I have a question about tempeature sensing in MEMS. I
>had heard something about sensing the temperature
>using a serpentine structure on the substrate.
>However; I could not find much information on the web
>regarding this. I am also interested in other methods
>of sensing temperature of the ambient air in the same
>scale.
>
>It would be a great help to my efforts if somebody
>could suggest me a link or any literature to help me
>how it can be sensed.