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A novel tunable acceleration-thresholds switch device based on electrostatic force in controlling friction for desired acceleration-thresholds level is developed. Electrostatic forces based on desired friction are used to provide variable acceleration threshold level. The design concept is based on the fact that when acceleration is presented on the proofmass, an induced static friction will exactly cancel the effect of the acceleration. Upon the acceleration level is exceeding the maximum static friction, the proofmass engages movement in the acceleration direction and enter dynamic friction region. A contact pad is designed here to detect the on/off status of the accelerating proofmass. Dynamic simulation model, established by Matlab Simulink solver, indicated that the input signal is given with 10 triangular waves from 0.5g to 5g peak accelerations in 0.1sec duration, and the threshold switch gap is designed in 1 m. When V_C, are equal to 1V, 1.5V, and 1.8V respectively, there are 8 signals (from 1.5g to 5g), 5 signals (from 3g to 5g), and 3 signals (from 4g to 5g) exceeded 1 m threshold switch gap which demonstrated the effectiveness of the present design concept. Experimental results of the tunable acceleration-thresholds switch device will be reported in the near future.