Technology.

Optical sensing,
on a chip.

Optics

Optics is a cornerstone technology in sensing applications due to its ability to capture and analyze complex data through the properties of light. The wealth of information carried by light allows for versatile, sensitive detection of a wide range of substances and phenomena in complex samples such as multi-component mixtures or intricate material structures. Its non-invasiveness enables measurements without altering the target. Overall, the precision, non-destructive nature, and data-rich output of optics make it an indispensable tool for advancing sensing capabilities across various industries.

Chip integration

Integrated photonics, or the integration of optical systems on semiconductor chips, builds off the successes of the electronics industry over the last decades. The ability to design and manufacture chips that guide and manipulate light provides optical devices with the same advantages as electronic chips: the miniaturization of complex systems reduces the size, weight, and cost of devices while enhancing their performance. As photonic integrated circuits (PICs) can now be mass-produced with high precision and efficiency, photonic integration has become an indispensable technology with ever-increasing maturity and capabilities.

Mutiple sensors on one optical chip.

Our sensors combine established optical analysis methods, such as Raman spectroscopy, with integrated photonics, the ability to manipulate light on semiconductor chips. This brings new features to optical sensing that yield unique advantages for our sensors – and their users.

Click on the sensors in the image below to learn more

Raman Sensors
use inelastic light scattering to analyze molecular composition, or simply put – what and how much of it is inside of a bioprocess. They provide non-invasive, real-time data on metabolites, nutrients and byproducts – and importantly, they reduce the need for offline sampling.

pH Sensors
measure how acidic or basic the medium is. A shift in pH can slow growth or even kill cells. Cells need a stable and specific pH to function properly. Enzyme activity, nutrient solubility, and metabolic reactions all depend on it.

Biomass Sensors
track the turbidity and the number of cells in the culture. They detect changes in optical density or capacitance, giving real-time data on growth dynamics. This data helps regulate nutrient supply and detect culture health changes.

O₂ Sensors
measure dissolved oxygen. Aerobic fermentations require accurate oxygen monitoring. If levels drop too low, respiration slows, leading to reduced energy production and possible metabolic stress. Proper oxygenation maintains cell viability and productivity.

Temperature Sensors
maintain thermal stability. Heat fluctuations affect enzyme function, membrane integrity, and reaction rates. Bioprocesses require strict temperature control to ensure an optimized metabolic activity.

CO₂ Sensors
monitor carbon dioxide, a key byproduct of metabolism. Excess CO₂ alters pH and affects cellular respiration. Controlling CO₂ prevents shifts that lower productivity.

Raman pH Biomass O₂ Temperature CO₂

The benefits of waveguide-enhanced
Raman spectroscopy

Our first sensors rely on Raman spectroscopy, an established analytical method known for being quantitative, highly specific, and compatible with aqueous media. very versatile, as it does not necessarily require previous knowledge of the target species. It is fast and does not require sampling nor sample preparation, making ideally suited to real-time in-line measurements. Waveguide-enhanced Raman spectroscopy (WERS), also called “Raman-on-a-chip”, combines the features of Raman spectroscopy with those of integrated photonics to yield unique advantages for WERS sensors compared to traditional free-space based Raman probes:

                Cost
              
The ability to mass-produce semiconductor chips yields large economies of scale. The integration of components onto the chip also reduces the component count of the system. This results in a sharp diminution in the cost of optical probes.

                Size
              
Nanofabrication allows for the dense integration of optical components on a chip, eliminating the need for bulky, discrete free-space elements. Very long interaction lengths, up to several dozens of centimeters, can be defined on millimeter-sized chips.

                Sensitivity
              
The strong confinement of light in high-index contrast waveguides leads to a concentration of the electric field, that generates enhanced light-matter interactions: a stronger exciting field is delivered to the target molecules, resulting in a stronger Raman response. A larger fraction of the Raman signal is also collected. As this enhanced response is distributed all along the waveguide, WERS is particularly suited to the measurement of bulk solutions.

                Speed
              
Raman spectroscopy doesn’t require sample preparation, is non-destructive and label-free, resulting in measurements directly as the reaction happens. With high sensitivity, only seconds or a few minutes are needed to obtain high-quality data.

Real-time
insights.

Raman spectroscopy is already known for providing in-line, real-time information. Our Raman-on-a-chip sensors go a step further by expanding the range of situations in which Raman can be used: measurements in single-use systems, in small-volume samples, at several points in a reactor or along a line, are now possible. Their reduced footprint allows them to be placed at the exact place where the most relevant information is generated, providing faster response times for dynamic processes.