MISSION (Mid- Infrared Silicon Photonic Sensors for Healthcare and Environmental Monitoring)

Lead Research Organisation: University of Southampton
Department Name: Optoelectronics Research Centre (ORC)

Abstract

Silicon Photonics, the technology of electronic-photonic circuits on silicon chips, is transforming communications technology, particularly data centre communications, and bringing photonics to mass markets, utilising technology in the wavelength range 1.2 micrometres - 1.6 micrometres. Our vision is to extend the technical capability of Silicon Photonics to Mid -Infrared (MIR) wavelengths (3-15 micrometres), to bring the benefits of low cost manufacturing, technology miniaturisation and integration to a plethora of new applications, transforming the daily lives of mass populations. To do this we propose to develop low-cost, high performance, silicon photonics chip-scale sensors operating in the MIR wavelength region. This will change the way that healthcare, and environmental monitoring are managed. The main appeal of the MIR is that it contains strong absorption fingerprints for multiple molecules and substances that enable sensitive and specific detection (e.g. CO2, CH4, H2S, alcohols, proteins, lipids, explosives etc.) and therefore MIR sensors can address challenges in healthcare (e.g. cancer, poisoning, infections), and environmental monitoring (trace gas analysis, climate induced changes, water pollution), as well as other applications such as industrial process control (emission of greenhouse gases), security (detection of explosives and drugs at airports and train stations), or food quality (oils, fruit storage), to name but a few. However, MIR devices are currently realised in bulk optics and integrated MIR photonics is in its infancy, and many MIR components and circuits have either not yet been developed or their performance is inferior to their visible/near-IR counterparts.

Research leaders from the Universities of Southampton, Sheffield and York, the University Hospital Southampton and the National Oceanography Centre will utilise their world leading expertise in photonics, electronics, sensing and packaging to unleash the full potential of integrated MIR photonics. We will realise low cost, mass manufacturable devices and circuits for biomedical and environmental sensing, and subsequently improve performance by on-chip integration with sources, detectors, microfluidic channels, and readout circuits and build demonstrators to highlight the versatility of the technology in important application areas.

We will initially focus on the following applications, which have been chosen by consulting end users of the technology (the NHS and our industrial partners): 1) Therapeutic drug monitoring (e.g. vancomycin, rifampicin and phenytoin); 2) Liquid biopsy (rapid cancer diagnostics from blood samples); 3) Ocean monitoring (CO2, CH4, N2O detection).
 
Title New characterisation setup 
Description We have built a new characterisation photonics setup for measurements of Si and Ge chips at longer wavelengths. This setup is versatile and enables easy inclusion of new sources and detectors. 
Type Of Material Improvements to research infrastructure 
Year Produced 2022 
Provided To Others? Yes  
Impact The setup is available to researchers in Southampton and UK for the characterisation of integrated photonic circuits at various wavelengths. 
 
Title Dataset for: The Effect of Haematocrit on Measurement of the Mid-Infrared Refractive Index of Plasma in Whole Blood 
Description Dataset DOI: https://doi.org/10.5258/SOTON/D1621 Article DOI: https://doi.org/10.3390/bios11110417 This data is used in the article 'The effect of haematocrit on the mid-infrared refractive index of blood plasma,' published by Biosensors. The data contained in data.xlsx are those used to plot the figures in the article. Measurement data were collected by ATR-FTIR spectroscopy at the University of Southampton during December 2019. Full methodological details can be found in the article. The XY data for each figure are contained in separate worksheets within data.xlsx. Each dataset is labelled with its name and unit. For plots with several spectral traces with respect to wavenumber, each trace is sampled at identical wavenumbers so wavenumber is only listed once. Briefly, each figure shows: Figure 1: Absorbance spectra of (a) DI water, plasma and whole blood with haematocrit in the range 20-70%, (b) plasma and whole blood with haematocrit in the range 20-70% over a more limited frequency range (1370-1570 cm-1), and (c) absorbance at 1541 cm-1 with respect to haematocrit. Figure 2: Empirical effective penetration depth deff calculated from the measured absorbance and literature k values of water. The dashed trace at wavenumbers > 3700 cm^-1 show the region where deff has been calculated from a ratio where both quantities are approximately equal to zero so cannot be relied upon. Figure 3: Imaginary part of refractive index spectra k for water and whole blood with haematocrit in the range 20 - 70%. Figure 4: Real part of refractive index spectra n for water and whole blood with haematocrit in the range 20 - 70%. Figure 5: Error in (a) real and (c) imaginary parts of plasma refractive index due to haematocrit in the range 20 - 70%. (b) shows the maximum error in n, which occurs at 1560 cm^-1, with respect to haematocrit; (d) shows the corresponding behaviour for k, which occurs at 1541 cm^-1. The data may be reused under Creative Common Attribution v4.0. 
Type Of Material Database/Collection of data 
Year Produced 2021 
Provided To Others? Yes  
URL https://eprints.soton.ac.uk/451978/
 
Description Collaboration with the University of Tromso 
Organisation University of Tromso
Country Norway 
Sector Academic/University 
PI Contribution Fabrication of Si and Ge chips
Collaborator Contribution Expertise on gas sensing, spectroscopy, polymers for enrichment, usage of specialised setups, staff time
Impact not year available
Start Year 2021