Electronic nose – a machine's sense of smell

Sensor-based solutions combined with digitalization have led to a revolution within machine-based vision and hearing. Similarly, there is great potential in digitizing the sense of smell. The possibilities of using e-noses extend over a wide range of applications.

The sense of smell is complex and creating an e-nose that meets the needs you want is often challenging. A successful design involves making several well-balanced choices, ranging from an analysis of the odors (gas compositions) that may occur, to wise choice of hardware and software.

At RISE, we can help you with these choices and most steps in your innovation work. For example, we help you with sensor development, developing a prototype for a specific application or testing the sensors' response to exposure to gases or odors. Below is a selection of more expertise and application areas where RISE can contribute with expertise to help you move forward with your issues.

Sensor technology

A central part of creating an e-nose is to choose the gas sensors that it should be based uopn. The fundamental principle is to have a set of sensors, a sensor array, with different sensitivities to different gases. This matrix forms the basis for being able to create "fingerprints" for different types of odors.

When choosing sensors, several considerations must be made. What desirable properties should the e-nose have? What environment will it operate in? What cost is acceptable? What will be the energy-supply to the sensor system? At RISE, we have great expertise in sensor technology and can help in the selection process. We can either guide you through the wide range of existing commercial technologies or develop your own sensors that may suit your needs. For example, we can manufacture gas sensors based on semiconductor materials.

Another area where RISE is working is printed electronics, a technology that has advantages from a sustainability and cost perspective. The technology makes it possible, among other things, for the sensor matrix to be printed on a substrate that can be of A4 size. Materials such as paper, PET, polyamide or wood can be used. Eco-friendly inks can create wires and mounting surfaces. Diodes, capacitances, antennas can be printed using the same technology. All of this contributes to a high degree of recyclability. To help build prototypes and develop new products, RISE has access to CAD tools, labs for testing and certification. Follow the links at the bottom of the page to read more about what RISE does in sensor technology and related areas such as electronics and communication.

AI and Computing

The principle of an electronic nose is based on the existence of some type of recognition algorithm. It can be anything from a mathematical model based on known phenomena to statistical models and AI. At RISE, there are several experts who work with statistics, AI and deep learning.

Gas- och aromanalys

What we experience as smell is often a complex mixture of different substances that reach the olfactory epithelium in the nose. The signals from the olfactory receptors are passed on into the brain where they are interpreted together with a variety of other signals, such as temperature, the basic tastes and the feeling of heat that, for example, chili can give. These mechanisms within human sense of smell can be copied with an e-nose. When developing and training an e-nose, the content of the gas composition to which it is exposed needs to be well defined so that the e-nose can be calibrated. Depending on the stage of development, this can be done in different ways.

To identify the content of an unknown odorous mixture of different substances, aroma analysis is required. With gas chromatography – olfactometry, we can identify the chemical substances that cause the perceived odor and with this recipe then design a suitable test mix that the e-nose can be trained with. Scroll down and read more about RISE's different expertise in aromachemistry and sensory.

Tillämpningsområden, domänkunskap

The areas where an e-nose can be used are many. Examples of applications in food and agriculture can be to assess quality and spoilage, or to monitor/control plant or fermentation processes. Monitoring of bioprocesses also extends beyond the food sector.

In building physics and the indoor environment, it is possible to monitor hygiene in, for example, bathhouses or toilets with the aim of optimising cleaning or other maintenance. Other areas of application can be to detect moisture damage or vermin.

In healthcare, monitoring and diagnostics with the help of e-nose may be done.

In many cases, it is valuable to support an innovation project with domain knowledge in addition to the purely technical knowledge. At RISE, we have many employees with expertise in the domains mentioned above and many others.