Alternative energy generated from people’s footsteps in a crowded area is sufficient to power smart electronic devices with low consumption. This paper aims to present the development of an energy harvesting floor—called Genpath—using a rotational electromagnetic (EM) technique to generate electricity from human footsteps. The dynamic models of the electro-mechanical systems were developed using MATLAB^®/Simulink to predict the energy performances of Genpath and help fine-tune the design parameters. The system in Genpath comprises two main parts: the EM generator and the Power Management and Storage (PMS) circuit. For the EM generator, the conversion mechanism for linear translation to rotation was designed by using the rack-pinion and lead-screw mechanism. Based on the simulation analysis, the averaged energy of the lead-screw model is greater than that of the rack-pinion model. Thus, prototype-II of Genpath with 12-V-DC generator, lead-screw mechanism was recently built. It shows better performance when compared to the previous prototype-I of Genpath with 24-V-DC-generator, rack-pinion mechanism. Both prototypes have an allowable displacement of 15 mm. The Genpath prototype-II produces an average energy of up to 702 mJ (or average power of 520 mW) per footstep. The energy provided by Genpath prototype-II is increased by approximately 184% when compared to that of the prototype-I. The efficiency of the EM-generator system is ~26% based on the 2-W power generation from the heel strike of a human’s walk in one step. Then, the PMS circuit was developed to harvest energy into the batteries and to supply the other part to specific loads. The experiment showed that the designed PMS circuit has the overall efficiency of 74.72%. The benefit of the design system is for a lot of applications, such as a wireless sensor and Internet of Thing applications.

There is an interest in harvesting energy from people’s footsteps in crowded areas to power smart electronic devices with low consumption. The average power consumption of these devices is approximately 10 μW. The energy from our footsteps is green and free, because walking is a routine activity in everyday life. The energy floor is one of the most efficient pieces of equipment in vibration-based energy harvesting. The paper aims to improve the previous design of the energy floor—called Genpath—which uses a rotational electromagnetic (EM) technique to generate electricity from human footsteps. The design consists of two main parts of (1) the EM generator, including the lead-screw mechanism for translation-to-rotation conversion, and (2) the Power Management and Storage (PMS) circuit. The improvement was focused on the part of the EM generator. A thorough investigation of the design components reveals that the EM generator shaft in the previous Genpath design cannot continuously rotate when the floor-tile reaches the bottom end, resulting in no energy gain. Therefore, a one-way clutch is implemented to the system to disengage the generator shaft from the lead-screw motion when the floor-tile reaches the allowable displacement. During the disengagement, the EM generator shaft still proceeds with a free rotation and could generate more power. In our analysis, the dynamic model of the electro-mechanical systems with the one-way clutch was successfully developed and used to predict the energy performances of the VEH floors and fine-tune the design parameters. The analytical result is shown that the spring stiffness mainly affects the force transmitted to the EM generator, and then the induced voltage and power of the generator, thus, the value of the stiffness is one of the critical design parameters to optimize. Finally, the new prototype consisting of 12-V-DC generator, mechanisms of lead-screw and clutch, as well as coil springs with the optimal stiffness of 1700 N/m was built and tested. The average energy produced by the new prototype is 3637 mJ (or average power of 3219 mW), per footstep which is 2935 mJ greater than that of the previous design. Moreover, to raise the social awareness about energy usage, the sets of Genpath have been used to organize an exhibition, “Genpath Empower our Journey”. The people who stroll forward on the paths can realize how much energy they gain from their footsteps.

Electrical devices are integral to daily life, but limited battery life remains a significant issue. A proposed solution is to convert dissipated energy from human motion into electricity using piezoelectric materials. This study investigates lead–zirconate–titanate (PZT) piezoelectric materials in bimorph configuration, conducts performance tests to understand their characteristics and determine the optimal load resistance, and develops an energy-harvesting prototype. Performance tests adjusted input parameters and varied load resistance and input magnitude to optimize power gained from the PZT bimorph. A suitable human movement for the application of the bimorph is a mouse-clicking motion by fingers. A prototype was created by integrating the bimorph into a computer mouse to capture energy from clicks. The results showed that the deformation rate of the PZTs, input magnitude, and resistance load were key factors in optimization. The bimorph configuration produced 0.34 mW of power and 5.5 V at an optimum load of 5072 Ω, requiring less effort to generate electricity. For the computer mouse energy harvester case, it yielded a total average power of approximately 38.4 μW per click with a click frequency of 4 Hz. This power could be used to support IoT devices such as human sensors (e.g., CO₂, temperature, and pulse sensors) and smart home sensors, enabling comprehensive health and environmental monitoring. In conclusion, input specifications, magnitude, and load resistance are essential for optimizing piezoelectric energy harvesters.

Electricity consumption in big cities has been increasing, especially in crowded areas. Although there is a large amount of energy usage in such places, people can generate the unnoticeable electrical energy from their footsteps. This paper aims to present the feasibility on development of an energy harvesting floor—called Genpath—using a rotational electromagnetic (EM) technique to generate electricity from the human’s footsteps. The system in Genpath comprises two main parts: the EM generator and the power management and storage circuit. After stepping over the floor, a rack-pinion mechanism under the floor converses the linear translation from a footstep into the rotation to drive a DC-generator to generate electricity. The EM generator yields an average energy per footstep of about 199 mJ (or average power of 331 mW) and the maximal voltage of 19 V at the rated 140-Ω load resistance. This amount of energy is sufficient for low power consumption electrical devices. The efficiency of the EM generator in Genpath is 16.6% based on the power generation from the heel strike of the human’s walk of 2 W per step. Among overall energy generated by the generator, 68% of generated energy is stored in the 9-V rechargeable batteries and the rest is supplied to the 4-V, LED instantaneous loads. The power management and storage circuit consisting of the diodes and DC-DC buck voltage converters was successfully designed. With 54% efficiency of the circuit, the average energy per step of 169 mJ can be stored in the rechargeable battery, and the other 4.7 mJ can be supplied to the LED loads.

Energy harvesting from human motions can extend battery lifespan and enhance mobile device convenience, with promising applications in military and medical fields. Knee motion is an excellent candidate for energy harvesting due to its significant recoverable negative work. This paper aims to design an Electro-Magnetic Energy Harvester (EMEH) that captures power from knee muscle work during walking. We used 2D motion capture techniques to obtain input data, including knee angular rotation and muscle work during walking. Position vectors were extracted with a motion tracker, angular positions were formulated, and the data were imported into MATLAB® Simscape MultibodyTM to develop a walking-leg model. The model obtained angular velocity, torque, and power, revealing an angular displacement within -60-0°, a maximum angular velocity of 5.42 rad/s, a maximum torque of 30 Nm, and an average power of 15.9 W. These results indicated both positive and negative work phases in one gait cycle, consistent with reference data, helping determine the energy harvester’s operating range. The EMEH model in MATLAB/Simulink® predicted the system’s output voltage and power, guiding prototype construction. Performance tests of the prototype showed a peak power output of about 8 W, with cumulative energy harvested at 5.5 J per gait cycle. With a prototype mass of 1.35 kg, the design achieved an average power density of 3.12 W/kg. Thus, our compact and lightweight EMEH prototype successfully converted the motion of the human knee into electricity while walking, achieving a power output suitable for practical applications.