We’ve already heard about so-called “microneedle patches” that are used for the painless and sustained release of medication through the skin. Now, MIT scientists have adapted the technology for the detection of spoiled food.
Ordinarily, microneedle patches consist of a small polymer square, the underside of which is covered in an array of tiny medication-filled spikes that are made of a water-soluble, biocompatible material. When that patch is pressed against the patient’s body, the spikes painlessly penetrate the top layer of skin. They then dissolve, releasing the medication into the bloodstream via the interstitial fluid that surrounds the skin cells.
Created by a team led by Asst. Prof. Benedetto Marelli and Prof. A. John Hart, the new MIT patch is made from silk fibroin – which is an edible protein extracted from moth cocoons – along with two types of “bioink” polymers. One of these is sensitive to a molecule in E.coli bacteria, while the other is sensitive to pH levels that are typically associated with food spoilage. In both cases, the polymer will change color if the targeted molecule or pH values are present.