In this work, gelatin is used not only as a substrate for the memory device but also as the resistive layer. This lightweight gelatin substrate (GS) will retain all of the desirable properties of plastic substrates, with the added advantages of being renewable, biodegradable, and inexpensive. GS is totally degraded after 18 days, showing excellent biodegradability in dry soil that can reduce the environmental impact effectively. Moreover, due to the substrate and resistive layer used of the same materials, it can be observed by the scanning electron microscope analysis that the films on GS both have smooth interfaces regardless of the gelatin layer or Ag electrodes after bending 1000 cycles. A strong interfacial adhesion leads to an efficient stress transfer underload, resulting in better structural stability and bending performance of the In/gelatin/Ag/GS device than those of the In/gelatin/Ag/PET device. The In/gelatin/Ag/GS device shows a stable retention time of more than 103 s and uniform current distribution, as well as the device with bending stress is capable to execute the ON/OFF ratio of over 104. This result exhibits the fabricating processes without a vacuum system and has broaden the application study of gelatin.

In this era of environmental protection and performance, the development of organic photodetectors is booming. The hydrogel material is beginning to attract attention because of its characteristics such as plasticity and ecofriendliness. However, it is still a challenge to achieve a high-speed response in biophotodetectors. Herein, the development of an organic one-dimensional nanostructured photodetector is proposed through rotary-jet injection of gelatin fibers incorporated with silver nanoparticles (Ag NPs). The variation in the photoelectric properties of thin-film, fibrous structures with different diameters of approximately 40 μm and 400 nm has been investigated. In particular, the gelatin–Ag NPs fiber photoreceptor with a diameter of about 400 nm improved the light-to-dark current ratio by up to 28000% higher than the film structure, with rise and decay times of only 0.23 and 0.56 s. In addition, the nanostructure effectively boosts the photocurrent and suppresses the dark current because of its confining domains. The Ag NPs within the gelatin nanofibers produce localized surface plasmon resonance in the UV-illumination environment, enhancing the light absorption of the photosensitive layer, which contributes directly to the increase in the rate of excitons. The novel structure of the hybridized gelatin nanofibers incorporating silver nitrate has offered the promising potential for organic photodetectors.

In this study, the dielectric layer of the xanthan gum resistive memory is treated by air plasma. Compared with the untreated original device, when the device is treated with plasma for 30 s, the activation energy is reduced from 0.17 to 0.13 eV, which helps to control the randomness of the path of trap hopping conduction. Thus, the average set voltage is reduced from 1.05 to 0.54 V, which makes the filament grow more easily. The fluctuation of I HRS decreased from 88.88% to 49.56%. This means that the uniformity and stability of the device can be effectively improved by the plasma treatment.

Natural materials are potential elements of environmentally friendly electronics for information storage. In this work, natural material-agar was used to fabricate the flexible resistive memory device. Agar is one of the most widely used biomaterials for tissue engineering, medicine, and other biotechnological applications. Agar is a suitable material for flexible electronics due to its good film formation, biocompatibility, low temperature solution-processibility, transparency, and flexibility. The flexible agar memory device exhibits the ON/OFF ratio of 103 under bending radius of 5 mm, good bending endurance, and a stable data retention time of over 104 s. Moreover, the agar could easily use leaf as substrate to make a fully biodegradable device. Due to the excellent flexibility of agar memory devices, agar is a candidate for becoming wearable and skin-compatible electronics.

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