Table 2.

Resonant devices comparison. The last column reports the power factor, i.e., the output power density normalized with the input acceleration (expressed in g=9.81 m/s²).

Reference	Material		dij [pm/V]	Vdevice [mm3]	Vpiezo [mm3]	fn [Hz]	RL [Ω ]	Vout [V]	Pdensity [W/cm3]	Power Factor [W/(g2cm3)]
	Name	Mode
[78]	AlN	d31	-	0.5	0.0004	1.4 × 103	650 × 103	1.6	4 × 10-3	248 × 10-6
[48]	PZT	d31	320	212.5	80.4	223.8	9.9 × 103	-	77 × 10-6	1.4 × 10-6
[61]	PZT	d33	-	-	0.00002	13.9 × 103	5.2 × 106	2.4 dc	-	-
[63]	PZT	d33	100	3.5	0.014	118.1	4.5 × 106	4.7	136 × 10-6	543 × 10-6
	PZT	d31	-55	3.5	0.014	130.8	11 × 103	0.77	1.9 × 10-3	7.8 × 10-3
[57]	PZT	d33	100	1.1	0.003	243	2 × 106	2 rms	1.6 × 10-3	6.4 × 10-3
	PZT	d31	-55	1.1	0.003	243	9.9 × 103	1.5 rms	2 × 10-3	8.1 × 10-3
[77]	PZT	d15	700	171.2	65	73	2.2 × 106	6.2	51 × 10-6	-
[76]	PZT	d15	741	4.8	2.5	45	1.6 × 106	19 × 10-3 rms	87 × 10-6	67.8 × 10-3
[74]	PMN-PT	d15	3,080	24,100	156	-	91 × 103	11.3	29 × 10-6	189 × 10-9
[35]	ZnO	d31	10	-	9.7	10 × 106	500 × 106	8 × 10-3	4 × 10-6	624 × 10-15
[68]	MFC	d33	400	340	120	22.5	4 × 106	-	494 × 10-6	17.1 × 10-3
[69]	PVDF	d33	33	549.5	24.2	1.5	10 × 106	-	364 × 10-6	-