# Multi-Unit Coupled Motion Hybrid Generator Based on a Simple Pendulum Structure
## 3 Results and Discussion  
### Structure and Working Principle of MCM-HG  
The structure and working principle of the MCM-HG are shown in Figure 1. The overall structure is rectangular, designed based on a simple pendulum structure, effectively integrating eight power generation units. The device is divided into two layers by a partition that features a U-shaped track. The upper layer includes two TENG units (P-TENG) and two PENG units, while the lower layer includes two TENG units (S-TENG) and two EMG units (P-EMG and C-EMG). This layered design maximizes the utilization of device space. The swinging block is composed of a magnet, which serves as a mass block to provide excitation for the power generation units and is also an essential part of the two EMG units, as shown in Figure 1a. Each power generation unit in the upper layer consists of five contact-separation TENGs and five PENGs, as shown in Figure 1b. The TENG friction layer consists of weakly magnetic silicon steel sheets and PTFE films, while the PENG is made of a PZT piezoelectric ceramic plate. The weakly magnetic silicon steel sheet with the PTFE film is fixed at the top of the MCM-HG structure, and the weakly magnetic silicon steel sheet with the PZT piezoelectric ceramic plate is attached to the pulley clamp. This design combines the TENG units with the PENG units to achieve coupled motion between the two units. Each fan-shaped power generation unit in the lower layer is constructed from an acrylic plate and a PTFE film, consisting of six pairs of contact-separation TENGs and four spiral PCB coils, as shown in Figure 1c. The acrylic plate, chosen for its high strength, light weight, and excellent mechanical support properties, serves as the skeleton of the fan-shaped structure. An acrylic plate of the same thickness as the PCB coil is selected, with a shape cut out in the middle to embed the PCB coil. The PTFE film and copper sheet, serving as the friction layer of the TENG, are attached to the structure composed of the acrylic plate and the PCB coil. Each acrylic plate is connected to the supporting ramp via a PTFE film; the physical images of each unit and the entire device are detailed in Figure S1-S5 in the Supporting Information. This design combines the TENG units with the EMG units, achieving coupled motion between the two units while effectively solving the problem of the large volume and heavy weight of traditional coils, thereby improving space utilization. Figure 1d explains the working principle of the device: when the device is tilted or subjected to horizontal inertial forces, the simple pendulum swings back and forth, thereby activating the TENGs, EMGs, and PENGs. The TENGs undergo contact separation, the magnetic flux through the EMG coils changes, and the PENGs deform to generate electrical energy. This process converts the mechanical energy from ocean waves into electrical energy. Figure 1e illustrates the working principle of the PENG units. The PENG and TENG units adopt a shared-carrier architecture design, with both units sharing a weakly magnetic silicon steel sheet substrate. Upon external excitation, the TENG unit undergoes contact separation, transmitting force to the silicon steel sheet and causing it to bend. The bending of the silicon steel sheet subsequently deforms the PZT ceramic sheet, where the piezoelectric effect induces the separation of positive and negative charges within the crystal. This charge imbalance generates a potential difference between the electrodes, producing current in the external circuit. The motion between the PENG and TENG units exhibits a certain phase difference, constituting phase-shifted motion. Taking the 0.5 Hz (T = 2 s) case where both units generate one output cycle as an example, TENG completes contact-separation and dominates output during 0-120 ms (forward) and 820-940 ms (reverse), while PENG achieves maximum bending and dominates output during 140-180 ms  
Figure 1: Structural design and working mechanism diagram of MCM-HG.