Multi-groove microneedles based wearable colorimetric sensor for simple and facile glucose detection

Microneedle technology is one of the advanced technologies in the field of biomedical engi-neering in recent years. It can penetrate the skin with minimal invasion for continuous health care monitoring. However, the current microneedles production process is complex, thus it can't be widely used. This paper demonstrates a one-step preparation method for multi-groove microneedle(MN) arrays based on the refraction index variations of polyethylene glycol di-acrylate (PEGDA) in the process of photopolymerization. The multi-groove microneedle can penetrate the skin and extract skin interstitial fluid (ISF) by capillary action. Hydrodynamic simulations showed that the liquid was risen in the multi-groove MNs by capillary force. Glu-cose was successfully extracted from mice and analyzed using a paper-based glucose sensor in-tegrated with the multi-groove MNs. The results reveal that the multi-groove MNs have potential for continuous glucose monitoring and precise diagnosis of diabetes.