A microfabricated lab-on-chip with three-dimensional electrodes for microscopic observation of bioelectromagnetic effects of cells

Electromagnetic (EM) signals are widely used in electronic instruments and biomedical systems and might have affected the human bodies surrounded by them. However, the interaction mechanism of EM signals with biological structures is poorly understood. We propose a micro-fabricated low-frequency EM stimulation lab-on-chip with three-dimensional interdigital electrodes for observation of cell lines with microscope. The field strength between the electrodes at various frequencies is estimated through simulation. An electric field strength of 4.45 Vrms/m is reached in the culture medium with a 10 Vpp, 10 kHz input signal. According to the simulation results, the high end of the applicable frequency range of the testbench is 3 MHz. A prototype is fabricated using full-wafer microfabrication techniques. The impedance of the prototype between 20 Hz and 30 MHz is characterized. Moreover, human cell line HEK293T is cultured in the testbench for 24 h and observed using microscope to check the biocompatibility of the electrodes. The prototype is thus applicable to long-term microscopic observation of cell lines for study of EM effect on biological structures. The 24-h cell culturing experiment with and without EM stimulation with the proposed prototype shows that the cell growth is obviously affected by a 10 kHz EM signal.