Inkjet-printed, functional heterolayers of ZnO@CuO for stoma pouch monitoring

Many bowel cancer patients are in need of an artificial stoma as part of their surgical treatment, and associated post-surgical odours caused by leaking stoma pouches may lead to social isolation, which is why inconspicuous monitoring of this situation is important for affected persons. The integration of micro- and nanotechnology may offer low-cost, low-power consumption and small solutions to this challenge. To this end, we present an inkjet-printed, heterostructured gas sensor that has been built by incorporating nanosized p-type semiconducting CuO in a porous n-type ZnO matrix. The functional layer is fabricated using a combination of a colloidal suspension and sol-gel approach optimized for inkjet printing thus offering an industry-ready method for integration of nanomaterials in microelectromechanical systems (MEMS) structures. Using a thermal modulation scheme we enhance the information content and classify different events. We demonstrate that a simple MEMS device using a novel hetero-nanomaterial may be used to reliably identify situations where stoma pouch content escapes.