Chips and Technologies

Chip-based sensors and actuators

Chip-based sensors and actuators are revolutionizing the field of medical engineering. Ever more complex functions are integrated in systems-on-chip. Medical diagnostic ands and treatment require rich and accurate sensing and measurement functions, which will be greatly enhanced by the use of Terahertz waves. The small electromagnetic wavelength in the Terahertz spectrum – around 100 µm – enables probing and imaging on this microscopic length scale. The chip size itself, including a Terahertz antenna, can be as small as one millimeter in diameter. Such miniaturized Terahertz chips can record imaging data, such as the inner shape of blood vessels. The terahertz waves can also identify particle size and difference in material; thus, cells can be identified by diameter or shape.

THz waves are sensitive to variations in ion concentration – enabling in-situ and localized measurement of important biomedical parameters such as potassium concentration, in a "contactless" way, with biologically safe THz waves. 

The fundamental miniaturization limit given by the electromagnetic wavelength is matched by Terahertz chip technology, enabling a revolutionary new class of miniaturized sensors, which can be applied within the region of interest inside the human body. This will afford a localized view of rich information from within the body, as opposed to todays view from the outside. 

Electronic THz chips

Electronic THz chips are based on advanced semiconductor processes, including silicon and other specialized semiconductor materials (e.g., graphene and indium phosphide, InP). Recent advances include high-efficiency multi-spectral THz sources and very sensitive detectors, which can even be integrated into camera chips for imaging, for rich data collection. Flexible THz sensors are based on Graphene for on-body sensing of motion and skin surface conditions. InP technology enables compact and efficient THz detection-and-sensing in one chip. 

THz spectroscopic material recognition is based on photonic InP chips, enabling ultra-wideband wireless sensing of the surroundings. Electronic radar chips with integrated antenna give high resolution size measurements, perhaps of the diameter of blood vessels. Even the electrical power for these on-chip sensor systems can be supplied by Terahertz waves, opening up the possibility of a millimeter-sized autonomous in-body sensing technology.

Photonic integrated circuits

Photonic integrated circuits (PICs) are extensively used in various fields, including medical applications. There are several use cases including photonic gas sensors, breath analysis or trace gas monitoring, and wearable sensors. Also, Terahertz radiation has demonstrated a great potential in medical applications, mainly due to its non-invasive and label-free nature. Especially, skin tissue is an optimal sample for the application of THz-based methods due to the small penetration depth. 

The rapid development of PICs for THz technologies now opens up a path towards miniaturized photonic sensors for non-invasive diagnostics and for stimulation of biomedical processes in a living skin tissue for regeneration and cancer treatment [1-3].


[1] I. Mohammad et al, „Photonic Non-Invasive mmW and THz Imaging for Non-Melanoma Skin Cancer Detection,” IWMTS 2022, Duisburg, Germany

[2] I. Mohammad et al, “Multi-Spectral Photonic THz Imaging using MUTC-PDs and Dielectric Rod Waveguide Antennas,” IRMMW-THz 2023, Montreal, Canada

[3] M. Grzeslo et al, “Development of a 3D Printed Dual-Band mmWave and THz Near-Field Microscope for Skin Cancer Detection,” IRMMW-THz 2023, Montreal, Canada