Table 3.

The performance comparison in the literatures.

Researcher	Length sensing element	Width sensing element	Probe sensing element	Static Pressure	Surface analysis
Tyan et al. [8]	1	1	1	○	X
Tang and Sun [11]	3	7	9	○	X
Jim et al. [13]	2	2	4	X	X
Our proposed	4	3	12	○	○