Implantable electronics are an interesting technology. They can, for example, continuously monitor cellular electrical activity in real time. However, because these devices have to interact directly with the biofluids in the body, preventing them from failing due to corrosion or current leakage is a challenge. Often, such devices need to be encapsulated. Single-crystalline silicon carbide (SiC) could be an alternative stable material, but it is usually not flexible enough for implantable electronics. Using it in the form of thin films with nanometer thickness (nanomembranes) could solve this problem.
Hoang-Phuong Phan, Griffith University, Brisbane, Australia, and Northwestern University, Evanston, IL, USA, John A. Rogers, Northwestern University, Nam-Trung Nguyen, Griffith University, and colleagues have created a stable, thin, flexible, semiconducting implantable device. The researchers grew crystalline cubic SiC nanomembranes on a silicon substrate using an epitaxial growth method. These nanomembranes were then transferred onto a polyimide substrate.
Tests showed that the device is stable towards hydrolysis and there is no obvious permeation of water or non-sodium ions after 60 days. The device can interact directly with the surrounding biofluids and tissues and can be used to sense changes in the temperature and localized strain, among other stimuli, without needing to be encapsulated. Due to the device’s chemical stability in biofluids, water barrier properties, and low permeability to various ions, it is thought that it could be stable in biological environments for decades.
- Long-Lived, Transferred Crystalline Silicon Carbide Nanomembranes for Implantable Flexible Electronics,
Hoang-Phuong Phan, Yishan Zhong, Tuan-Khoa Nguyen, Yoonseok Park, Toan Dinh, Enming Song, Raja Kumar Vadivelu, Mostafa Kamal Masud, Jinghua Li, Muhammad J.A. Shiddiky, Dzung Dao, Yusuke Yamauchi, John A. Rogers, Nam-Trung Nguyen,
ACS Nano 2019.