A New Label-Free and Contactless Bio-Tomographic Imaging with Miniaturized Capacitively-Coupled Spectroscopy Measurements

Abstract

A new bio-imaging method has been developed by introducing an experimental verification of capacitively coupled resistivity imaging in a small scale. This paper focuses on the 2D circular array imaging sensor as well as a 3D planar array imaging sensor with spectroscopic measurements in a wide range from low frequency to radiofrequency. Both these two setups are well suited for standard containers used in cell and culture biological studies, allowing for fully non-invasive testing. This is true as the capacitive based imaging sensor can extract dielectric spectroscopic images from the sample without direct contact with the medium. The paper shows the concept by deriving a wide range of spectroscopic information from biological test samples. We drive both spectra of electrical conductivity and the change rate of electrical conductivity with frequency as a piece of fundamentally important information. The high-frequency excitation allows the interrogation of critical properties that arise from the cell nucleus.

Regional Admittivity Reconstruction With Multi-Frequency Complex Admittance Data Using Contactless Capacitive Electrical Tomography

“…The sensitivity matrix, that reflects the relationship between the complex dielectric properties and the boundary complex admittance measurements, is required in this work. With (4) as the basement, the sensitivity matrix is established with the adaptions of the complex capacitance system [20]. Therefore, the integral relation between the complex admittance 𝑌 𝑐𝑜𝑚𝑝𝑙𝑒𝑥 and the distribution of conductivity and permittivity at the angular frequency ω can be represented as:…”

“…CCERT-related studies for medical applications so far mainly focus on the conductivity reconstruction [17][18][19][20]. In 2016, the Complex-Valued, Multi-Frequency Electrical Capacitance Tomography (CVMF-ECT) came up by Zhang reconstructed the permittivity and conductivity through the boundary complex admittance measurements in a simulated ECT sensor system for industrial application [21].…”

3D Image Reconstruction Capability of Peripheral On-chip ECT Sensor

“…In recent decade, the miniaturisation of electrical tomography sensor array has been blooming with the advancement of microfluidics and lab-on-chip applications. The electrical impedance tomography (EIT) sensor array for example, has been miniaturised to fit in miniature sensing chamber of sizes ranging from 12 mm to 35 mm and the size of microelectrodes ranges from 0.6 mm to 5 mm [13], [14], [15], [16]. The miniature EIT sensors has been investigated in 3D imaging of cells [17], 2D visualisation of drug responds on cells in scaffolds [18] and 3D imaging of 3D cultured cells in scaffold [13].…”