an accelerometer or a seismometer using an in - plane suspension geometry having a suspension plate and at least one fixed capacitive plate . the suspension plate is formed from a single piece and includes an external frame , a pair of flexural elements , and an integrated proof mass between the flexures . the flexural elements allow the proof mass to move in the sensitive direction in the plane of suspension while restricting movement in all off - axis directions . off - axis motion of the proof mass is minimized by the use of intermediate frames disbursed within and between the flexural elements . intermediate frames can include motion stops to prevent further relative motion during overload conditions . the device can also include a dampening structure , such as a spring or gas structure that includes a trapezoidal piston and corresponding cylinder , to provide damping during non - powered states . the capacitive plate is made of insulating material . a new method of soldering the capacitive plate to the suspension plate is also disclosed .