An apparatus including a robot arm comprising a wrist, and an end effector. The wrist includes a frame member. The frame member includes a first material having a first coefficient of thermal expansion. The end effector is connected to the wrist at a connection. The end effector is configured to support a substrate thereon. The end effector includes a first member and a second member. At least one of the first and second members has a different second material with a different second coefficient of thermal expansion. The connection includes the first and second members being stationarily attached to each other with a portion of the frame member sandwiched therebetween. The connection is configured to substantially prevent the different respective coefficients of thermal expansion to deflect the end effector relative to the wrist when the end effector and wrist are heated and/or cooled.