Amini Shahram, Choi Hongbin, Seche Wesley, Blagojevic Alexander, May Nicholas, Lefler Benjamin M, Davis Skyler L, Elyahoodayan Sahar, Tavousi Pouya, May Steven J, Caputo Gregory A, Lowe Terry C, Hettinger Jeffrey, Shahbazmohamadi Sina
Research and Development, Pulse Technologies Inc., Quakertown, PA, USA.
Biomedical Engineering Department, University of Connecticut, Storrs, CT, USA.
Microsyst Nanoeng. 2024 Sep 9;10(1):125. doi: 10.1038/s41378-024-00754-w.
Over the last two decades, platinum group metals (PGMs) and their alloys have dominated as the materials of choice for electrodes in long-term implantable neurostimulation and cardiac rhythm management devices due to their superior conductivity, mechanical and chemical stability, biocompatibility, corrosion resistance, radiopacity, and electrochemical performance. Despite these benefits, PGM manufacturing processes are extremely costly, complex, and challenging with potential health hazards. Additionally, the volatility in PGM prices and their high supply risk, combined with their scarce concentration of approximately 0.01 ppm in the earth's upper crust and limited mining geographical areas, underscores their classification as critical raw materials, thus, their effective recovery or substitution worldwide is of paramount importance. Since postmortem recovery from deceased patients and/or refining of PGMs that are used in the manufacturing of the electrodes and microelectrode arrays is extremely rare, challenging, and highly costly, therefore, substitution of PGM-based electrodes with other biocompatible materials that can yield electrochemical performance values equal or greater than PGMs is the only viable and sustainable solution to reduce and ultimately substitute the use of PGMs in long-term implantable neurostimulation and cardiac rhythm management devices. In this article, we demonstrate for the first time how the novel technique of "reactive hierarchical surface restructuring" can be utilized on titanium-that is widely used in many non-stimulation medical device and implant applications-to manufacture biocompatible, low-cost, sustainable, and high-performing neurostimulation and cardiac rhythm management electrodes. We have shown how the surface of titanium electrodes with extremely poor electrochemical performance undergoes compositional and topographical transformations that result in electrodes with outstanding electrochemical performance.
在过去二十年中，铂族金属（PGMs）及其合金一直是长期植入式神经刺激和心律管理设备电极的首选材料，这是由于它们具有卓越的导电性、机械和化学稳定性、生物相容性、耐腐蚀性、射线不透性以及电化学性能。尽管有这些优点，但PGM的制造过程极其昂贵、复杂且具有挑战性，还存在潜在的健康危害。此外，PGM价格波动大且供应风险高，再加上它们在地壳上层的浓度稀缺，约为0.01 ppm，且采矿地理区域有限，这凸显了它们被归类为关键原材料，因此，在全球范围内对其进行有效回收或替代至关重要。由于从已故患者身上进行死后回收和/或提炼用于制造电极和微电极阵列的PGM极为罕见、具有挑战性且成本高昂，所以，用其他能产生等于或大于PGM电化学性能值的生物相容性材料替代基于PGM的电极，是减少并最终替代长期植入式神经刺激和心律管理设备中PGM使用的唯一可行且可持续的解决方案。在本文中，我们首次展示了如何在广泛应用于许多非刺激型医疗设备和植入应用的钛上运用“反应性分级表面重构”新技术，来制造生物相容性好、低成本、可持续且高性能的神经刺激和心律管理电极。我们已经展示了电化学性能极差的钛电极表面如何经历成分和形貌转变，从而得到具有出色电化学性能的电极。
