Search

When one thinks about electrodes, especially ones meant for humans, one typically thinks of some kind of metal. Whether on the skin or in the brain, metal electrodes are characteristically expensive, stiff, non-efficient in electron-ion transduction, and prone to toxic metal ion by-products during stimulation. In order to circumvent these disadvantages, electrically-conductive laser-induced graphene (LIG) and mixed electron-ion conducting polymer (poly(3, 4‐ethylenedioxythiophene) polystyrene sulfonate – PEDOT:PSS) was leveraged to create a metal-free electrode combination that allows for an economical, soft, and organic electrode for applications on human skin. Compared to clinical-standard silver – silver chloride (Ag/AgCl) skin electrodes, the metal-free hydrogel electrodes show notable improvement in electrochemical stability and prolonged stable potentials during long-term DC stimulation (0.5–24 h). Recording and stimulation performance on human participants rivals that of Ag/AgCl, thus fortifying the notion that they are an appropriate progression to their noble metal counterparts.

The three main challenges of cancer treatment are metastases, recurrence, and acquired therapy resistance. These challenges have been closely linked to circulating cancer cell clusters. A detailed understanding of their genetic and morphological composition is essential. This will not only improve our knowledge of basic cancer biology but enable the successful development of much needed therapies preventing the three main challenges mentioned above. Extensive research effort is underway to isolate, capture, and analyze circulating tumor cells. However, few if any current efforts specifically target cancer cell clusters, and their much greater ability to initiate new tumors. Growing scientific consensus over the last five years has convincingly established the importance of targeting circulating cancer cell clusters verses individual CTCs to prevent the occurrence of metastatic disease. Based on the increased clinical importance of cancer cell clusters as the main driver of cancer metastasis, new and improved methods are much needed to access these larger multi-celled structures. Microfluidic devices offer a readily accessible platform for a customizable microenvironment for cell isolation and analysis. In this study, we show how a well-known passive micromixer design (staggered herringbone mixer - SHM) can be optimized to induce maximum chaotic advection within antibody-coated channels of dimensions appropriate for the capture of cancer cell clusters. The device’s principle design configuration is called: Single-Walled Staggered Herringbone (SWaSH). The preliminary empirical results of our work show that utilization of extensive simulation and modeling can accelerate the development of a working prototype that allows for target-specific cancer cell cluster isolation.