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Explora: Environment
and Resource Scalable nanofluidic photoreceptors

scale fabrication and integration of stimuli-responsive (Figure 1B and C). The osmotic current of pHANCs under
nanochannels remains challenging, which is primarily due light illumination is approximately 3 times higher than
to the poor chemical stability of nanoscale materials and that without light illumination (Figure 1C). Moreover,
the extreme difficulty in ensuring the consistency of pore the osmotic power density of pHANCs is correlated
structures. linearly with the light intensity within the range of 0 –
−2
Recently, Huang et al. reported a bioinspired 100 mW cm (Figure 1D). In a typical salt concentration
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nanofluidic photoreceptor constructed with highly gradient system of 0.5 M/0.01 M NaCl, the osmotic power
oriented nanochannels (pHANCs) and a self-powered density of pHANCs with an optimal amount of pyranine
−
ionic light sensor with massively integrated photoreceptor reaches 148.3 W m ² under illumination (Figure 1D),
units (Figure 1A). The pHANCs are two-dimensional outperforming commercial ion-exchange membranes
nanochannels obtained by stacking graphene oxide and previously developed ion-selective membranes.
modified with photo-responsive pyranine dye. These Importantly, the planar structure of the pHANCs is highly
channels exhibit outstanding ion selectivity and compatible with microfabrication techniques, allowing
permeability, leading to remarkable osmotic energy- for easy large-scale integration through serial and parallel
harvesting performance. Upon light irradiation at 405 nm, connections (Figure 1E). The integrated device maintains
ion transport within the nanochannels is significantly good performance comparable to that of individual
enhanced due to the light-induced excess surface charge biomimetic photoreceptor. A high osmotic voltage of

A

B C D

E F

Figure 1. Light-sensing nanochannels for self-powered ionic breakthroughs. (A) Schematic illustration of a biological visual system grounded in ion
channels. (B) Representation of osmotic energy harvesting through pHANCs. (C) Current-voltage curves of pHANCs recorded in a 50-fold NaCl
−2
concentration gradient, with and without light illumination. (D) Power generation of pHANCs at different light intensities (mW cm ) by mixing artificial
river water (0.01 M NaCl) and seawater (0.5 M NaCl). (E) Optical images of a magnified biomimetic photoreceptor. Scale bars: 5 mm (left); 1 mm (right).
(F) Electric voltage output of the biomimetic photoreceptor array in serial connections. The inset illustrates the serial connection scheme of biomimetic
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photoreceptors. Reproduced with permission from Huang et al. Copyright © 2024, The American Association for the Advancement of Science.
Abbreviation: pHANCs: Photo-responsive highly oriented nanochannels.

Volume 2 Issue 2 (2025) 2 doi: 10.36922/EER025120022