caa a22 4500 60547947X CHVBK 20210128100410.0 cr unu---uuuuu 210128e20150201xx s 000 0 eng 10.1007/s10544-014-9904-y doi (NATIONALLICENCE)springer-10.1007/s10544-014-9904-y Effect of bias voltage and temperature on lifetime of wireless neural interfaces with Al2O3 and parylene bilayer encapsulation [Elektronische Daten] [Xianzong Xie, Loren Rieth, Ryan Caldwell, Sandeep Negi, Rajmohan Bhandari, Rohit Sharma, Prashant Tathireddy, Florian Solzbacher] The lifetime of neural interfaces is a critical challenge for chronic implantations, as therapeutic devices (e.g., neural prosthetics) will require decades of lifetime. We evaluated the lifetime of wireless Utah electrode array (UEA) based neural interfaces with a bilayer encapsulation scheme utilizing a combination of alumina deposited by Atomic Layer Deposition (ALD) and parylene C. Wireless integrated neural interfaces (INIs), equipped with recording version 9 (INI-R9) ASIC chips, were used to monitor the encapsulation performance through radio-frequency (RF) power and telemetry. The wireless devices were encapsulated with 52nm of ALD Al2O3 and 6μm of parylene C, and tested by soaking in phosphate buffered solution (PBS) at 57°C for 4× accelerated lifetime testing. The INIs were also powered continuously through 2.765MHz inductive power and forward telemetry link at unregulated 5V. The bilayer encapsulated INIs were fully functional for ∼35days (140days at 37°C equivalent) with consistent power-up frequencies (∼910MHz), stable RF signal (∼−75 dBm), and 100% command reception rate. This is ∼10 times of equivalent lifetime of INIs with parylene-only encapsulation (13days) under same power condition at 37°C. The bilayer coated INIs without continuous powering lasted over 1860 equivalent days (still working) at 37°C. Those results suggest that bias stress is a significant factor to accelerate the failure of the encapsulated devices. The INIs failed completely within 5days of the initial frequency shift of RF signal at 57°C, which implied that the RF frequency shift is an early indicator of encapsulation/device failure. Springer Science+Business Media New York, 2015 Neural interface nationallicence Utah electrode array nationallicence Atomic layer deposited (ALD) Al2O3 nationallicence Parylene nationallicence Bilayer encapsulation nationallicence Continuous bias voltage nationallicence Accelerated aging nationallicence Long-term reliability nationallicence Xie Xianzong University of Utah, Salt Lake City, UT, USA aut Rieth Loren University of Utah, Salt Lake City, UT, USA aut Caldwell Ryan University of Utah, Salt Lake City, UT, USA aut Negi Sandeep University of Utah, Salt Lake City, UT, USA aut Bhandari Rajmohan University of Utah, Salt Lake City, UT, USA aut Sharma Rohit University of Utah, Salt Lake City, UT, USA aut Tathireddy Prashant University of Utah, Salt Lake City, UT, USA aut Solzbacher Florian University of Utah, Salt Lake City, UT, USA aut Biomedical Microdevices Springer US; http://www.springer-ny.com 17/1(2015-02-01), 1-8 1387-2176 17:1<1 2015 17 10544 https://doi.org/10.1007/s10544-014-9904-y text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s10544-014-9904-y text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Xie Xianzong University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Rieth Loren University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Caldwell Ryan University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Negi Sandeep University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Bhandari Rajmohan University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Sharma Rohit University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Tathireddy Prashant University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 700 1- Solzbacher Florian University of Utah, Salt Lake City, UT, USA aut NATIONALLICENCE 773 0- Biomedical Microdevices Springer US; http://www.springer-ny.com 17/1(2015-02-01), 1-8 1387-2176 17:1<1 2015 17 10544