Dual-Enhanced Sodium Alginate-Based Triboelectric Nanogenerator with PEI Doping and Microstructured Surface

Biomaterials-based triboelectric nanogenerators (TENGs) with excellent biocompatibility and biodegradability have attracted tremendous attention for wearable electronic devices, human–computer interaction, and implantable devices. How to improve their output performance through a simple method is still a challenge. In this work, we prepared a flexible, low-cost, green, and high-performance TENG (SA-TENG) assembled by a modified sodium alginate (SA) film. The SA was first modified by simply doping branched polyethylenimine (PEI), which has a high density of amino functional groups to boost its electron-donating ability. Then, the film surface was patterned with a microstructure by using sandpaper templates to enhance the effective contact area. With the combination of the two performance enhancement methods, the optimized SA-TENG has an open-circuit voltage of up to 490 V, a short-circuit current of 33 μA, a charge of 255 nC, and a peak power of 2.55 mW. The prepared device can be employed as an energy source to light LEDs and power electronic devices. In addition, the device can be applied as a self-powered wearable sensor for tactile sensing and physical motion monitoring. This work provides an efficient and simple method for enhancing the triboelectric properties of biomaterials for advanced energy applications.