This　paper　presents　an　equivalent　analytical　model　for　vibration　analysis　of　the　V-　and　Z-shaped　electrothermal　microactuators.　Considering　the　geometric　analogy　between　the　line-shaped　and　V/Z-shaped　beam,　the　analytical　model　for　vibration　of　the　line-shaped　beam　that　characterize　the　V-　and　Z-shaped　beams　is　established　first.　The　line-shaped　beam　provides　completely　the　same　boundary　conditions　and　geometric　dimensions　(beam　span,　width,　thickness,　and　shuttle　dimensions)　as　the　V-and　Z-shaped　beams,　except　for　the　inclined　angle　and　the　middle　step　beam,　namely　the　stiffness.　By　writing　the　frequency　of　the　line-shaped　beam　as　a　product　of　its　stiffness　and　the　term　determined　by　the　boundary　conditions,　the　first-order　natural　frequency　of　the　V-and　Z-shaped　beams　can　be　derived　by　substituting　their　stiffness　into　the　frequency　expression.　As　the　movement　of　the　shuttle　(i.e.,　the　stiffness)　does　not　contribute　higher　order　mode　shapes,　corresponding　higher-order　natural　frequencies　of　the　V-and　Z-shaped　beams　can　be　predicted　directly　with　the　line-shaped　beam　model.　Verification　of　the　vibration　model　for　the　line-shaped　beam　as　well　as　the　equivalent　approach　to　predicting　the　natural　frequencies　of　the　V-and　Z-shaped　beams　was　conducted　by　comparing　the　results　with　finite-element　simulation　data　using　ANSYS　software.　Results　show　that,　apart　from　some　inaccuracies　in　predicting　the　higher　order　frequencies　for　the　Z-shaped　beam,　this　equivalent　approach　is　accurate　for　the　first-order　frequency　of　the　V-　and　Z-shaped　beam　as　well　as　the　higher　order　frequencies　for　the　V-shaped　beam.　With　this　simple　equivalent　model,　it　is　possible　to　investigate　the　frequency　characteristics　of　the　two　typical　beams　thus　paving　the　way　for　control　and　improving　the　design　of　the　V-　and　Z-shaped　electrothermal　microactuators.