On the longevity and inherent hermeticity of silicon-ICs: evaluation of bare-die and PDMS-coated ICs after accelerated aging and implantation studies
2024

Evaluating the Longevity of Silicon Integrated Circuits for Neural Implants

Sample size: 74 publication 10 minutes Evidence: moderate

Author Information

Author(s): Nanbakhsh Kambiz, Shah Idil Ahmad, Lamont Callum, Dücső Csaba, Akgun Ömer Can, Horváth Domonkos, Tóth Kinga, Meszéna Domokos, Ulbert István, Mazza Federico, Constandinou Timothy G., Serdijn Wouter, Vanhoestenberghe Anne, Donaldson Nick, Giagka Vasiliki

Primary Institution: Delft University of Technology, Delft, The Netherlands

Hypothesis

Can polydimethylsiloxane (PDMS) effectively enhance the longevity of silicon integrated circuits (ICs) in physiological environments?

Conclusion

PDMS-coated regions of silicon ICs showed limited degradation over 12 months, indicating its potential as a suitable encapsulant for long-term implantation.

Supporting Evidence

  • ICs were electrically biased and monitored for stable performance even when exposed to physiological fluids.
  • Material analysis showed degradation in bare regions but limited degradation in PDMS-coated regions.
  • Guidelines were proposed to enhance the longevity of implantable ICs based on the findings.

Takeaway

Silicon chips used in brain implants can last a long time if they are coated with a special rubbery material called PDMS, which helps protect them from damage.

Methodology

The study involved accelerated in vitro and in vivo aging studies of silicon ICs, comparing electrical and material performance of bare die and PDMS-coated regions over one year.

Limitations

The study primarily focused on two foundries, which may limit the generalizability of the findings to other manufacturing processes.

Participant Demographics

Rats were used for the in vivo study, with a total of 6 rats implanted with 12 ICs.

Digital Object Identifier (DOI)

10.1038/s41467-024-55298-4

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