Table 2.

Summary of pros and cons of each wireless power transfer method according to the literature review [160]. IC – inductive coupling, CC – capacitive coupling, MF – mid-field, FF – far-field, US – ultrasound, OW – optical, ME – magnetoelectric.

	IC	CC	MF	FF	US	OW	ME
advantages	Efficiency Small RX Well established	Delivered power Efficiency	Efficiency Small RX	High depth TX practicality	High depth Small RX High efficiency	High efficiency	Low absorption Small RX
limitations	Low depth Misalignment	Low depth High RX area TX practicality	Misalignment TX practicality	Efficiency High absorption	Misalignment Losses in interfaces Losses in bone	Low depth Absorption in tissue TX practicality Misalignment	Misalignment Early development Efficiency