Adaptive Triboelectric Nanogenerators for Long-Term Self-Treatment: A Review

Abstract

Triboelectric nanogenerators (TENGs) were initially invented as an innovative energy-harvesting technology for scavenging mechanical energy from our bodies or the ambient environment. Through adaptive customization design, TENGs have also become a promising player in the self-powered wearable medical market for improving physical fitness and sustaining a healthy lifestyle. In addition to simultaneously harvesting our body's mechanical energy and actively detecting our physiological parameters and metabolic status, TENGs can also provide personalized medical treatment solutions in a self-powered modality. This review aims to cover the recent advances in TENG-based electronics in clinical applications, beginning from the basic working principles of TENGs and their general operation modes, continuing to the harvesting of bioenergy from the human body, and arriving at their adaptive design toward applications in chronic disease diagnosis and long-term clinical treatment. Considering the highly personalized usage scenarios, special attention is paid to customized modules that are based on TENGs and support complex medical treatments, where sustainability, biodegradability, compliance, and bio-friendliness may be critical for the operation of clinical systems. While this review provides a comprehensive understanding of TENG-based clinical devices that aims to reach a high level of technological readiness, the challenges and shortcomings of TENG-based clinical devices are also highlighted, with the expectation of providing a useful reference for the further development of such customized healthcare systems and the transfer of their technical capabilities into real-life patient care.

Keywords: adaptivity; clinical treatment; self-diagnosis; self-powered device; triboelectric nanogenerator.

Figure 4

(a) Schematic diagram briefly showing the in situ air gap generation of NSTENG. Reprinted with permission from [49]. 2021, Elsevier. (b) Working principle of the relevant vagus nerve stimulation system, schematically showing the generation of two-phase electrical signals and the path of vagus nerve stimulation. (c) Schematic diagram of the power generation principle of the vagus nerve stimulation device at different gastric motility stages. Reprinted with permission from [50]. 2018, nature. (d) LED bulbs lit by BISS implanted in rabbits and the open circuit voltage and short circuit current of BISS during operation. Reprinted with permission from [52]. 2019, ACS.

Figure 6

(a) Application diagram of MXene/NH2−MWCNTs-based TENG. Reprinted with permission from [60]. 2022, Elsevier. (b) The preparation process of ITO-Van, which is able to specifically capture Staphylococcus aureus, including the immobilization of dopamine and vancomycin on the etched surface of ITO glass. (c) Schematic diagram of staphylococcus aureus detection using a self-powered biosensor system. In the process of detecting Staphylococcus aureus, a liquid environment is assumed, and a vertical contact-separation TENG is used as the voltage signal source. Reprinted with permission from [62]. 2022, Elsevier. (d) SANES attached to the abdominal surface used in a respiratory monitoring application scenario; SANES schematic diagram; and an enlarged view of PAN nanofiber film and PA 66 nanofiber film coated with an Au electrode layer. Reprinted with permission from [63]. 2021, Elsevier.

Figure 9

(a) Human limb movement activates the WP−TENG to achieve bone repair. Reprinted with permission from [71]. 2022, John Wiley and Sons. (b) Schematic diagram of M-ESD system for hair regeneration. Reprinted with permission from [74]. 2019, ACS. (c) Electrical muscle stimulation powered by TENGs. Reprinted with permission from [77]. 2019, ACS.

Figure 11

(a) Schematic diagram of a cube polysaccharide battery composed of the soft natural hydrogel. Reprinted with permission from [84]. 2021, Elsevier. (b) Schematic diagram of sterilization system. Cu₂O and Staphylococcus aureus. Reprinted with permission from [85]. 2022, Elsevier. (c) Schematic diagram of S-TENG disinfection system, including an S-TENG, a power management system (PMS) with rectifier, and a disinfection filter for inactivating microorganisms in water. Reprinted with permission from [86]. 2022, John Wiley and Sons. (d) The schematic diagram of ultrasonic-driven vagus nerve electrical stimulation based on implanted soft HENG and the manufacturing process of HENG. Reprinted with permission from [90]. 2022, Elsevier.

Figure 1

Triboelectric nanogenerators for long-term self-treatment and self-diagnosis.

Figure 2

(a) Vertical contact-separation mode. (b) Lateral sliding mode. (c) Single-electrode mode. (d) Freestanding triboelectric-layer mode. Reprinted with permission from [39]. 2020, copyright John Wiley and Sons.

Figure 3

(a) Design scheme and schematic diagram of the rapid degradation of P-TENGs showing the tiny cellulose particles and gelatin capsules. Reprinted with permission from [41]. 2022, Elsevier. (b) Schematic diagram of the working mechanism of the single-electrode mode triboelectric system. Reprinted with permission from [42]. 2019, Elsevier. (c) Structure diagram of the 3D-printed breath-driven TENG. Reprinted with permission from [43]. 2022, Springer Nature.

Figure 5

(a) Triboelectric nanogenerator sensor with a double sandwich structure. Reprinted with permission from [54]. 2022, Nano Research. (b) Integrated description of SUPS for non-invasive multi-index pulse monitoring. (c) Schematic diagram of the structure of SUPS. Optical photo of the built SUPS. Reprinted with permission from [55]. 2021, Elsevier. (d) FPS test radial pulse wave. Reprinted with permission from [56]. 2022, Elsevier.

Figure 7

(a) Preparation method of catechol chitosan diatom hydrogel, and the mechanism of enhancing the cohesion of catechol chitosan diatom hydrogel. Optical image. (b) Typical symptoms of Parkinson’s disease. Schematic diagram of catechol chitosan diatom hydrogel triboelectric nanogenerator and vibration sensor. Reprinted with permission from [64] 2021, Elsevier.

Figure 8

(a) Schematic diagram of electrode implant solution. Cut the skin, and introduce an electric stimulation cuff on the left sciatic nerve of the rats. Place Cs TENG as an energy collector at the waist of the rat, and connect the electrode with the encapsulated platinum wire to ensure that the damaged area is located between the two electrodes. Reprinted with permission from [69]. 2022, John Wiley and Sons. (b) Use of TENG-IT to restore touch. TENG-IT is implanted under the skin (desensitized fingers). Reprinted with permission from [70]. 2021, ACS.

Figure 10

(a) Biodegradation in rats. (b) BN-TENG implantation: pictures of BN-TENG and the change in state at the site of implantation after suture. Reprinted with permission from [81]. 2018, John Wiley and Sons. (c) Representative images of wounds on days 1, 3, 7, and 14. Reprinted with permission from [82]. 2022, Elsevier. (d) Images of skin wounds from different treatment groups taken on days 0, 3, 5, 7, 9, and 11. Reprinted with permission from [83]. 2022, Elsevier.

Figure 12

(a) Schematic diagram of a wearable sign language voice translation system. Reprinted with permission from [91]. 2020, Elsevier. (b) Real−time angle signal, angle speed, and photos within the range of motion. (c) Schematic diagram of rehabilitation brace system. Reprinted with permission from [93]. 2022, Elsevier.

Figure 13

(a) Diagram of the equipment and schematic diagram of the co-culture of cells and DOX after electrical stimulation. Reprinted with permission from [94]. 2022, Frontiers. (b) Structural diagram of this TENG. (c) Schematic diagram of the sustainable release of salicylic acid. Reprinted with permission from [95]. 2020, John Wiley and Sons.