Control of polymers' amorphous-crystalline transition enables miniaturization and multifunctional integration for hydrogel bioelectronics

Sizhe Huang; Xinyue Liu; Shaoting Lin; Christopher Glynn; Kayla Felix; Atharva Sahasrabudhe; Collin Maley; Jingyi Xu; Weixuan Chen; Eunji Hong; Alfred J Crosby; Qianbin Wang; Siyuan Rao

doi:10.1038/s41467-024-47988-w

Control of polymers' amorphous-crystalline transition enables miniaturization and multifunctional integration for hydrogel bioelectronics

Nat Commun. 2024 Apr 25;15(1):3525. doi: 10.1038/s41467-024-47988-w.

Authors

Sizhe Huang^{1

2}, Xinyue Liu³, Shaoting Lin⁴, Christopher Glynn², Kayla Felix², Atharva Sahasrabudhe⁵, Collin Maley², Jingyi Xu², Weixuan Chen², Eunji Hong^{1

2}, Alfred J Crosby⁶, Qianbin Wang^{7

8}, Siyuan Rao^{9

10}

Affiliations

¹ Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA.
² Department of Biomedical Engineering, University of Massachusetts, Amherst, MA, USA.
³ Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing, MI, USA.
⁴ Department of Mechanical Engineering, Michigan State University, East Lansing, MI, USA.
⁵ Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, MA, USA.
⁶ Department of Polymer Science and Engineering, University of Massachusetts, Amherst, MA, USA.
⁷ Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA. qbwang@binghamton.edu.
⁸ Department of Biomedical Engineering, University of Massachusetts, Amherst, MA, USA. qbwang@binghamton.edu.
⁹ Department of Biomedical Engineering, Binghamton University, State University of New York, Binghamton, NY, USA. syrao@binghamton.edu.
¹⁰ Department of Biomedical Engineering, University of Massachusetts, Amherst, MA, USA. syrao@binghamton.edu.

Abstract

Soft bioelectronic devices exhibit motion-adaptive properties for neural interfaces to investigate complex neural circuits. Here, we develop a fabrication approach through the control of metamorphic polymers' amorphous-crystalline transition to miniaturize and integrate multiple components into hydrogel bioelectronics. We attain an about 80% diameter reduction in chemically cross-linked polyvinyl alcohol hydrogel fibers in a fully hydrated state. This strategy allows regulation of hydrogel properties, including refractive index (1.37-1.40 at 480 nm), light transmission (>96%), stretchability (139-169%), bending stiffness (4.6 ± 1.4 N/m), and elastic modulus (2.8-9.3 MPa). To exploit the applications, we apply step-index hydrogel optical probes in the mouse ventral tegmental area, coupled with fiber photometry recordings and social behavioral assays. Additionally, we fabricate carbon nanotubes-PVA hydrogel microelectrodes by incorporating conductive nanomaterials in hydrogel for spontaneous neural activities recording. We enable simultaneous optogenetic stimulation and electrophysiological recordings of light-triggered neural activities in Channelrhodopsin-2 transgenic mice.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Animals
Channelrhodopsins / chemistry
Channelrhodopsins / genetics
Channelrhodopsins / metabolism
Hydrogels* / chemistry
Male
Mice
Mice, Transgenic*
Microelectrodes
Nanotubes, Carbon / chemistry
Optogenetics* / methods
Polymers* / chemistry
Polyvinyl Alcohol* / chemistry
Ventral Tegmental Area / physiology

Substances

Polyvinyl Alcohol
Hydrogels
Polymers
Nanotubes, Carbon
Channelrhodopsins
polyvinyl alcohol hydrogel

Grants and funding

R00 MH120279/MH/NIMH NIH HHS/United States