The KERMIT patch is a soft, disposable skin patch, currently under development, that combines sweat stimulation, microfluidics, sensing and wireless electronics on a single printed platform for non-invasive detection and screening of kidney dysfunction. Screen printed iontophoresis electrodes gently induce sweat, which is guided through a thin microfluidic layer to dedicated sensing zones. There, printed electrochemical sensors detect key kidney biomarkers such as creatinine, cystatin C and urea directly in sweat. A low power chip processes the signals and transmits the data via an integrated antenna to a smartphone or reader for medical assessment. The printed patch stack is designed with bio based and recyclable materials wherever possible while maintaining comfort and reliable skin adhesion, offering a promising route toward more sustainable, sweat based screening tools for chronic kidney disease and related disorders.