Science - USA (2022-02-25)

signal measured by the skin-gate transistor
(Fig. 5K), showing the dynamic activity of the
alpha rhythm coupled with cyclic eye closing
and opening.

Conclusions

Here, we report on mechanically robust
freestanding VDWTFs assembled from 2D
nanosheets for highly stretchable, adaptable,
conformal, and breathable membrane elec-
tronics. The bond-free VDW interfaces among
the nanosheets enable sliding and rotating
degrees of freedom to render extraordinary
mechanical flexibility, stretchability, and mal-
leability. The staggered nanosheet architecture
also features a percolation network of nano-
channels for excellent permeability or breath-
ability. The ultrathin freestanding VDWTFs
are structurally robust with an excellent me-
chanical match to soft biological tissues, nat-
urally adapting to microscopic topographies

and directly integrating with living organisms

through highly conformal interfaces, endow-

ing living organisms with electronic functions.

The VDWTFs can thus function as versatile

electronic membranes that actively adapt to

the environment while retaining sufficient

electronic performance for sensing, signal am-

plification, processing, and communication.

REFERENCESANDNOTES

1. G. D. Spyropoulos, J. N. Gelinas, D. Khodagholy,Sci. Adv. 5 ,
   eaau7378 (2019).


2. I. Youet al.,Science 370 , 961–965 (2020).


3. F. Ershadet al.,Nat. Commun. 11 , 3823 (2020).


4. Q. Liet al.,Nano Lett. 19 , 5781–5789 (2019).


5. S. Wanget al.,Nature 555 , 83–88 (2018).


6. K. Simet al.,Sci. Adv. 5 , eaav5749 (2019).


7. E. Stavrinidouet al.,Sci. Adv. 1 , e1501136 (2015).


8. K. Kwonet al.,Nat. Electron. 4 , 302–312 (2021).


9. J. Kooet al.,Nat. Med. 24 , 1830–1836 (2018).


10. M. Hanet al.,Nat. Biomed. Eng. 4 , 997–1009 (2020).


11. M. Bariya, H. Y. Y. Nyein, A. Javey,Nat. Electron. 1 , 160– 171
    (2018).
    12. J. A. Rogers, R. Ghaffari, D.-H. Kim, Eds.,Stretchable Bioelectronics
    for Medical Devices and Systems(Springer, 2016).
    13. S. H. Chaeet al.,Nat. Mater. 12 , 403–409 (2013).
    14. J. Yoonet al.,Nat. Mater. 7 , 907–915 (2008).
    15. D.-Y. Khang, H. Jiang, Y. Huang, J. A. Rogers,Science 311 ,
    208 – 212 (2006).
    16. D.-H. Kimet al.,Science 333 , 838–843 (2011).
    17. L. Tianet al.,Nat. Biomed. Eng. 3 , 194–205 (2019).
    18. Z. Huanget al.,Nat. Electron. 1 , 473–480 (2018).
    19. J. Rivnayet al.,Nat. Rev. Mater. 3 , 17086 (2018).
    20. Y. Fang, X. Li, Y. Fang,J. Mater. Chem. C 3 , 6424–6430 (2015).
    21. L. Caiet al.,Nat. Commun. 8 , 496 (2017).
    22. Z. Yanet al.,Adv. Sci. 4 , 1700251 (2017).
    23. Y. Liuet al.,Macromolecules 48 , 6534–6540 (2015).
    24. J. N. Colemanet al.,Science 331 , 568–571 (2011).
    25. Z. Linet al.,Nature 562 , 254–258 (2018).
    26. Z. Lin, Y. Huang, X. Duan,Nat. Electron. 2 , 378–388 (2019).
    27. D. McManuset al.,Nat. Nanotechnol. 12 , 343–350 (2017).
    28. J. W. Jeonget al.,Adv. Mater. 25 , 6839–6846 (2013).
    29. J. A. Rogers, T. Someya, Y. Huang,Science 327 , 1603–1607 (2010).
    30. Y.-K. Leeet al.,Sci. Adv. 6 , eaax6212 (2020).
    31. C. E. Carraher Jr.,Giant Molecules: Essential Materials for
    Everyday Living and Problem Solving(Wiley, ed. 2, 2003).
    32. Y.-Q. Zhenget al.,Science 373 , 88–94 (2021).
    33. B. Xu, X. Chen,J. Mater. Res. 25 , 2297–2307 (2010).
    34. O. Scott, M. Begley, U. Komaragiri, T. Mackin,Acta Mater. 52 ,
    4877 – 4885 (2004).

858 25 FEBRUARY 2022¥VOL 375 ISSUE 6583 science.orgSCIENCE

A B C

DE G

H I

J

K

F

Fig. 5. Skin-gate VDWTF transistors for monitoring transient skin
potentials.(A) Relative drain current (DIds) of a skin-gate VDWTF transistor
stimulated by 5 kHz 0.1-V 20-ms-wide gate pulses at aVdsof 0.1 V. (B) The
response time of the skin-gate VDWTF transistor to a square gate pulse
(blue dashed line). (C) Normalized transconductance at various frequencies.
(D) Schematic diagram of the ECG measurement with aVdsof 0.5 V and
aVgof 0.5 V. (EandF) The ECG signals measured by the skin-gate transistor
(red line) and Ag/AgCl electrode (black line) (E) before and (F) during
human exercise. a.u., arbitrary units. (G) Zoomed-in view of boxed portion

in (F), showing clear P, QRS, and T waves from the skin-gate transistor

but only a QRS wave and motion artifacts from the Ag/AgCl electrodes.

(H) Schematic diagram of the EEG measurement. (I) Recorded EEG

signals using a skin-gate transistor when a human subject was engaged in

two mental states (closed eyes and open eyes). Eye blink artifacts are

also visible. (J) Fast Fourier transform (FFT)–processed frequency

distributions of the EEG signals in (I). (K) Time-frequency spectrograms

of the EEG signals recorded during cyclic eye closing and opening,

showing dynamic activity of the alpha rhythm at ~10 Hz.

RESEARCH | RESEARCH ARTICLES