Microfluidic Biosensor Based on Microwave Substrate-Integrated Waveguide Cavity Resonator

Table 3

Comparison of our proposed biosensor with other RF MEMS bio/chemical sensors.

Reference	Target biomaterial/chemical	Sensing technology	Frequency (GHz)	Frequency shift (MHz)	Physical size (mm × mm)	Electrical size^†
[15]	Glucose in human serum	MEMS	9.2	90, 160	2 × 0.9	0.2 λg × 0.1 λg^φ
[46]	Cancerous colorectal cell	MEMS	5	30	N/A	N/A
[47]	Cancerous glial cells	MEMS	13	35	15 × 5	1.27 λg × 0.4 λg^φφ
[48]	Glucose in aqueous solution	MEMS	7.5	20	1 × 1	N/A
[49]	Ethanol, methanol, acetone, ammonia	CMOS-MEMS	0.12	13.2	2 × 0.03	N/A
This work^†††††	Fibroblast cells	SIW	13.48	20, 170	33 × 28	2.26 λg × 1.92 λg

^φDielectric constant of substrate (gallium arsenide) is assumed 11~13. ^φφDielectric constant of substrate (fused silica) is assumed 3.8. ^{†††††}20 MHz and 170 MHz shifts in resonance frequency are relative to the PBS and empty microwell, respectively. ^†λ_g is the guided wavelength in the structure.