What can we do with our smartphones nowadays? We can keep connected with our families and friends by making phone calls and sending text messages. We can also surf the internet and access global information in most places in the world thanks to the fast and widely deployed mobile network. Some may also say we can play video games and entertain ourselves thanks to the high computational performance smartphones nowadays provide. However, have you thought of using your smartphone to test whether our food is safe to eat or not in the future? That is what we are trying to achieve in our European Union Marie Curie Innovative Training Networks (ITN) FoodSmartphone project.
Firstly, what is food safety? I think food safety is the objective where people can enjoy safe and nutritious food without causing illness. Within our FoodSmartphone project, we are developing smartphone-based devices that can be used to tackle food safety issues caused by contaminants including food allergy, pesticide, pathogens, and natural toxins. Food allergy is caused by over-reaction of our immune systems on the intake food allergens. Pesticide residue in food could cause human endocrine disruptions. Our food will expire and smell badly mostly due to the pathogens (e.g., E. coli) in our food. The pathogens in food is also a major source of food-borne gastroenteritis. And the nature toxins presented in fungus (e.g., poisonous mushrooms) and seafood (e.g., puffer) could be deadly even with small doses.
Is there any way we can detect those containments in our food? The most instinctive way is using our five senses (vision, smell, taste, tactile, and hearing). We can identify whether the fruits are matured and fresh by their colour. We can also smell our food to decide whether they have gone bad – if the food smells awful we usually will avoid it. We will also avoid eating bitter food because that usually indicates toxicity. We can tell the fruit is not fresh if it touches extremely soft. And we can knock on watermelon and listen to the sound to judge if it is matured. Even though testing food using our five senses is fast, it requires lots of experience and is subjective and qualitative. Therefore, we need scientific instruments to objectively test our food. Up to date, there are mainly two instrumental food testing models: sending the samples to the labs and bringing the labs to the samples.
The conventional food testing in the labs requires bulky and expensive lab-instruments and professional personnels. However, such resource demanded model can hardly catch up with the rapid boost of food testing needs in our society. And the food samples are prone to deterioration and cross-contamination during their delivery to the labs.
Currently, most portable food testing in China is still conducted by transporting bulky instruments over cars and vans to the testing sites and then operated by the professionals. A few commercially available consumer-oriented devices that works with smartphones to display their testing results are still too expensive to be widely adopted. Therefore, there is a potential for ultra-portable and consumer-friendly food testings that can be operated on-site and by even novice users in everyday scenario.
We are currently developing a smartphone-based versatile optical reader. Users can change components on this device to adapt most smartphone models, different light sources and assay platforms. The reason why such versatility is necessary is because people own smartphone with very different specifications such as dimension and camera positioning. Also, the optical assays for the detection of different containments may work on different assay platforms and in different lighting conditions. Two simple examples of such optical assays are the pH test strip where pH of solution can be evaluated through its colour change and the pregnancy test using lateral flow devices where both test and control lines will show up if a specific indicator presented in urine.
The designed smartphone apparatus can be produced by even low-end 3D-printers. The cost for purchasing such 3D-printers and materials to manufacture the device is affordable for people even living in resource limited regions. The two images above show the 3D-printed prototype attached to an Android smartphone and its modulated design. The publication can be open accessed here, and the smartphone apparatus is open sourced here.
Above is a short video demonstrating how 3D-printing works. Essentially, it works by layer by layer 2D-printing and produces the final 3D model.
After having been in the FoodSmartphone project for more than two years, I returned to my previous middle school during this new year break to introduce the FoodSmartphone concept and stimulate the next generation on their interest in science. Though reassumed that this dissemination would be a great opportunity for me to practice my presenting skill as I need to explain the abstract and complex concepts to middle school students within 20 minutes, I did not expect how enthusiastic the students would be after the dissemination. My spectral thanks to people who made this trip possible.
At the end, thank you very much for your time on reading this blog.
Until next time,