Standard characterization methods of biological cells are time consuming and may reduce cell viability by staining them with markers. An alternative fast and non-destructive method is developed using impedance spectroscopy, which has potential applications in biology. The technique is used to identify tumor cells in mice, detect bacterial eye infections, monitor fruit ripening, and measure sweat lactate concentration in humans by using a skin sensor. These applications often require a portable measurement system. Therefore, three portable systems were designed and tested. It has been shown that the method can be further improved by four-terminal measurements. For extension of the method in the millimeter-wave frequencies, full electromagnetic simulation of the chip has been carried out, and electrodes and interconnections have been adjusted accordingly. weiterlesen