THE MECHANICAL-PROPERTIES OF THE RUBBER ELASTIC POLYMER POLYDIMETHYLSILOXANE FOR SENSOR APPLICATIONS

Polydimethylsiloxane (PDMS) is a commercially available physically and chemically stable silicone rubber. It has a unique flexibility with a shear elastic modulus G approximate to 250 kPa due to one of the lowe st glass transition temperatures of any polymer (T-g approximate to -1 25 degrees C). Further properties of PDMS are a low change in the shea r elastic modulus versus temperature (1.1 kPa degrees C-1), virtually no change in G versus frequency and a high compressibility. Because of its clean room processability, its low curing temperature, its high f lexibility, the possibility to change its functional groups and the ve ry low drift of its properties with time and temperature, PDMS is very well suited for micromachined mechanical and chemical sensors, such a s accelerometers (as the spring material) and ISFETs (as the ion selec tive membrane). It can also be used as an adhesive in wafer bonding, a s a cover material in tactile sensors and as the mechanical decoupling zone in sensor packagings.