High resolution surface imaging arrays interrogated with microfluidically controlled metalized plates

Microfluidically controlled metalized plates are proposed for the first time as a low-cost interrogation mechanism for high resolution surface imaging arrays. The pixels of the envisioned imaging system are formed as a dense array of sub-wavelength size slot spiral resonators etched at the ground plane of a microwave substrate. The resonance frequencies of these resonators shift based on the dielectric properties of the material sample within their close proximity. Interrogation of the resonance frequency of each resonator is done by utilizing metalized plates as RF shorts between read-out microstrip lines and resonators. The metalized plates can be repositioned within the microfluidic channels by use of a single micropump unit to sequentially interrogate resonance frequencies of all pixels to extract an image. The concept is introduced through simulations and experiments carried over a 1D material sample. An example 2D imaging system is also presented (through computational simulations) for imaging of tumorous excised breast tissue. The proposed technique alleviates the needs for expensive/complex RF switch based interrogation circuitries or bulky/slow mechanical raster scans.