MEMS actuators with stress releasing design

Abstract

The micro-electromechanical (MEMS) actuator comprises a hot arm member and a cold arm member. The cold arm member comprises at least two longitudinally spaced-apart flexors. The actuators may also be constructed with at least one among the hot arm member and the cold arm member comprising at least one spring section. The stress in this improved MEMS actuator is more uniformly distributed, thereby reducing the mechanical creep and improving its reliability as well as its operation life.

1 . A micro-electromechanical (MEMS) actuator comprising:
 a hot arm member;   a cold arm member;   wherein the cold arm member comprises at least two longitudinally spaced-apart flexors.   
   
   
       2 . The MEMS actuator of  claim 1 , wherein one of the flexors is adjacent to an end of the cold arm member that is anchored to a substrate. 
   
   
       3 . The MEMS actuator of  claim 1 , wherein the two flexors have a substantially similar width. 
   
   
       4 . The MEMS actuator of  claim 1 , wherein the two flexors have a different length. 
   
   
       5 . The MEMS actuator of  claim 1 , wherein the hot arm member comprises two spaced-apart portions, each provided at one end with a corresponding anchor pad connected to a substrate, the portions of the hot arm member being connected together at a common free end that is opposite their anchor pads. 
   
   
       6 . The MEMS switch of  claim 5 , wherein the cold arm member comprises an anchor pad connected to the substrate, one of the flexors being adjacent to the anchor pad of the cold arm member. 
   
   
       7 . The MEMS switch of  claim 1 , wherein the flexors of the cold arm member are separated by a wider portion of the cold arm member, the wider portion being attached to the hot arm member by a tether. 
   
   
       8 . A micro-electromechanical (MEMS) switch comprising:
 a first cantilever MEMS actuator comprising a first hot arm member, a first cold arm member and a first dielectric tether attaching together a free end of the first hot arm member and a free end of the first cold arm member;   a second cantilever MEMS actuator comprising a second hot arm member, a second cold arm member and a second dielectric tether attaching together a free end of the second hot arm member and a free end of the second cold arm member; and   at least two longitudinally spaced-apart flexors positioned on the cold arm member of at least one among the first and the second MEMS actuator.   
   
   
       9 . The MEMS switch of  claim 8 , wherein the at least two spaced-apart flexors of a same cold arm member are separated by a wider portion of the cold arm member, the wider portion being attached to the corresponding hot arm member by an additional tether. 
   
   
       10 . A micro-electromechanical (MEMS) actuator mounted on a substrate, the MEMS comprising:
 a hot arm member;   a cold arm member;   wherein at least one among the hot arm member and the cold arm member comprises at least one spring section.   
   
   
       11 . The MEMS actuator of  claim 10 , wherein the hot arm member comprises two spaced-apart portions, each provided at one end with a corresponding anchor pad connected to the substrate, the portions of the hot arm member being connected together at a common free end that is opposite the anchor pads, at least one of the portions of the hot arm member comprising one of the at least one spring section adjacent to the anchor pads. 
   
   
       12 . The MEMS actuator of  claim 11 , wherein each portion of the hot arm member comprises one of the at least one spring section. 
   
   
       13 . The MEMS actuator of  claim 12 , wherein the spring sections of the portions of the hot arm member are symmetrically disposed. 
   
   
       14 . The MEMS actuator of  claim 10 , wherein the cold arm member comprises one of the at least one spring section. 
   
   
       15 . The MEMS actuator of  claim 10 , wherein both the hot arm member and the cold arm member comprise one of the at least one spring section. 
   
   
       16 . The MEMS actuator of  claim 10 , wherein each spring section comprises a plurality of segments configured in zigzags. 
   
   
       17 . The MEMS actuator of  claim 16 , wherein the zigzags are at a substantially right angle. 
   
   
       18 . A micro-electromechanical (MEMS) switch comprising:
 a first cantilever MEMS actuator attached to a substrate and comprising a first hot arm member, a first cold arm member and a first dielectric tether attached to a free end of the first hot arm member and a free end of the first cold arm member;   a second cantilever MEMS actuator attached to the substrate and comprising a second hot arm member, a second cold arm member and a second dielectric tether attached to a free end of the second hot arm member and a free end of the second cold arm member; and   at least one spring section positioned on at least one among the hot arm member and the cold arm member of at least one of the MEMS actuators.   
   
   
       19 . The MEMS switch of  claim 18 , wherein each hot arm member comprises two spaced-apart portions, each provided at one end with a corresponding anchor pad connected to the substrate, the portions of the hot arm member being connected together at a common free end that is opposite the anchor pads, at least one of the portions of each hot arm member comprising one of the at least one spring section. 
   
   
       20 . The MEMS switch of  claim 19 , wherein each portion of each hot arm member comprises one of the at least one spring section. 
   
   
       21 . The MEMS switch of  claim 20 , wherein the spring sections of the portions of a same hot arm member are symmetrically disposed with reference to a longitudinal axis of the hot arm member. 
   
   
       22 . The MEMS switch of  claim 18 , wherein both the hot arm member and the cold arm member of a same actuator comprise one of the at least one spring section. 
   
   
       23 . The MEMS switch of  claim 18 , wherein each spring section comprises a plurality of segments configured in zigzags. 
   
   
       24 . The MEMS switch of  claim 23 , wherein the zigzags are at a substantially right angle.