果冻传媒

Our modern society is driven by technological innovations to make our economy more efficient, our vehicles safer, and our lives more comfortable by an increasing degree of automation.

Automated monitoring and control systems are in constant need of accurate reliable measurement data. This is provided by a growing number of sensors that can keep track of material composition, temperature, vibrations, deformations, forces and many other parameters.

Light matters

To be used in consumer applications and industrial processes, these sensing systems need to be small, robust, and cost-efficient. Optical sensors use the interaction of light with its surrounding to measure ambient parameters and material properties. The light spectrum consists of light with different wavelengths, which interacts differently with materials and optical structures.

This effect can be used to encode the desired parameter in the optical spectrum. Commonly a spectrometer is used to measure the light spectrum and decode the value of the target parameter. While they can provide high wavelength resolution, spectrometers are typically bulky, expensive and too fragile for harsh sensing environments.

Spectral sensors

For her PhD research, Anne van Klinken developed spectral sensors on a chip as an alternative to spectrometers for optical material analysis and the readout of optical sensors.

Each spectral sensor has a footprint of about 2 mm x 2mm and consists of an array of photodetector pixels. Through the use of a scalable fabrication process using optical lithography and a special process pioneered at 果冻传媒 to integrate an InP membrane on silicon wafer (called IMOS), the spectral sensors were manufactured in the NanoLab@果冻传媒 cleanroom facility at the 果冻传媒 campus.

Organic materials

The photodetector pixels are designed such that each pixel is sensitive to a different wavelength band. All the pixels together can capture a 鈥渟pectral fingerprint鈥� of the light that is send to the spectral sensor.

When collecting light reflected from organic materials 鈥� such as food products, plastics or pharmaceuticals, the chemical composition can be determined from the spectral fingerprint using a chemometric model. For optical sensors, which can translate tiny changes in the desired measurand into a small change of the optical spectrum, the collected light can be directly related to the measurand.

This is specifically useful for optical biosensors, which have great application potential in point-of-care diagnostics, but currently they still rely on spectrometers for their readout.

Optical biosensor

Van Klinken and her colleagues demonstrated that the newly developed spectral sensors can be used as an accurate optical biosensor and that it delivers even more precise results than a bench-top spectrometer.

Both for the non-destructive analysis of the composition of organic materials as well as for the readout of optical sensors, the spectral sensors developed by Van Klinken in her PhD research have the potential to bring sensing applications in the agri-food industry, health-care sector and plastic recycling processes one step closer to large-scale applications and thereby contribute to a healthy and sustainable society.

Title of PhD thesis: . Supervisors: Andrea Fiore and Jaime G贸mez Rivas.