PurposeA　piezoelectric　vibration　energy　harvester　(PVEH),　as　a　self-power　device　that　can　convert　ambient　vibration　energy　into　electric　energy,　has　extensive　application　prospects　in　power　supply　for　microsensors　used　in　Internet　of　Things　(IoT).　How　to　match　the　ambient　vibration　frequencies,　which　are　always　random　and　broadband,　is　a　key　point　to　design　a　PVEH.　In　this　study,　a　tuning　fork-shaped　PVEH　with　pendulum　impact-driven　enhancement　is　proposed　for　energy　harvesting　from　broadband　low-frequency　vibration.MethodsThe　impact-driven　tuning　fork-shaped　PVEH　with　adjustable　mechanisms　is　first　designed,　and　the　working　principle　is　introduced　in　detail.　Dynamic　equations　are　established,　and　the　vibration　characteristics　are　analyzed　by　comparing　the　results　of　the　finite　element　analysis　(FEA)　and　numerical　simulation,　where　the　natural　frequencies　and　modes　are　studied,　and　the　effects　of　pendulum　impact-driven　enhancement　on　the　energy　harvesting　performance　are　analyzed　in　detail.ResultsThe　results　show　that　the　proposed　PVEH　can　obtain　0.6　mW　and　6.4　mW　output　powers　when　the　excitation　frequencies　are　5　Hz　and　34　Hz　with　0.5　g　excitation　amplitude　and　the　optimum　load　resistance,　respectively.　Finally,　experimental　investigations　are　carried　out　to　verify　the　energy　harvesting　performance,　and　19　light-emitting　diodes　(LEDs)　are　lit　up　to　assess　the　prospective　applications　of　the　proposed　impact-driven　PVEH.ConclusionsThe　investigation　demonstrates　that　the　pendulum　impact-driven　could　enhance　the　low-frequency　responses,　which　helps　the　PVEH　achieve　the　energy　harvesting　from　broadband　low-frequency　ambient　vibration.