A novel, piezoelectric material-based eye-blink sensor system for wireless bionic control

Abstract

A novel, piezoelectric material-based eye-blink sensor system for wireless bionic control, comprising: a piezoelectric eye-blink sensor module with PVDF / ZnO nanorods configured to generate an electrical signal in response to mechanical stress or stretching caused by eyelid movements; a flexible carrier material on which the piezoelectric sensor module is attached, allowing direct application to the skin; an energy management unit integrated into the piezoelectric sensor module, which serves to extract energy from the generated electrical signals in order to operate the system autonomously; a computing unit coupled with the sensor module and the power management unit, configured to process the electrical signals to detect eye blink patterns using an embedded algorithm; a wireless communication module connected to the computing unit, configured to transmit processed data to an external control unit for wireless bionic control applications; The system is designed to operate as an energy-autonomous sensor node with minimal dependence on external energy sources.

Description

[0001] The present invention relates to a field of assistive technology and, more particularly, to a novel piezoelectric material-based eye blink sensor system for wireless bionic control.

[0002] Eye blink and eye movement detection has been extensively researched for applications such as detecting eye fatigue and abnormal blinking. Advances in eye movement tracking systems (EMTS) have led to various techniques reported in the scientific literature. Non-invasive methods include the use of expensive high-resolution cameras or EEG sensor mounts to detect eye movements. In contrast, skin-mounted sensors based on piezoelectric principles (piezo-EMTS) offer advantages such as small size, low power consumption, and high sensitivity. These flexible sensor modules can be applied directly to the eyelids and operate as self-powered sensor nodes, using materials that are non-toxic to the skin.

[0003] Materials such as ZnO, lead zirconate titanate, and gallium nitride (GaN) have been investigated for their effectiveness in piezo-EMTS applications. Polyvinylidene fluoride (PVDF) is inherently piezoelectric, converting mechanical energy into electrical signals. However, its practical use is hampered by processing challenges, a low piezoelectric coefficient, and a limited Curie temperature. In contrast, piezoelectric semiconductor materials such as ZnO are lighter and more robust than their ceramic counterparts. The integration of piezoelectric nanomaterials into the PVDF matrix overcomes these issues by enhancing the piezoelectric response through mechanisms such as internal strain and interfacial effects, enabling efficient charge transport.

[0004] PVDF-based piezoelectric nanocomposites, including those with ZnO nanorods on flexible substrates, therefore demonstrate significant potential for various applications. These materials enable advances in energy harvesting and sensing technologies. Ongoing research to refine fabrication techniques and optimize material properties underscores their pivotal role in driving innovations that meet the evolving demands of modern engineering and technology. Therefore, there remains a pressing need to further advance the development and application of piezoelectric-based eyeblink sensor systems, particularly the use of PVDF / ZnO nanocomposites on flexible substrates.

[0005] To solve this problem, the present invention provides a novel piezoelectric material-based eye blink sensor system for wireless bionic control.

[0006] The system can enable passive eye movement detection and energy detection.

[0007] The system is designed to collect and transmit data effectively.

[0008] The system is designed to operate as an autonomous unit with its own power supply, minimizing the need for external energy.

[0009] The system is designed to ensure efficient data processing and communication between the eye blink sensor and the control module.

[0010] The system provides a small, wearable, flexible, self-powered eye blink sensor node for wireless control, using novel piezoelectric sensing materials such as PVDF / ZnO nanorods.

[0011] The system is designed to be lighter and more robust.

[0012] The system offers an energy- and cost-efficient method for wireless bionic control.

[0013] In one embodiment, a novel piezoelectric material-based eye blink sensor system for wireless bionic control is provided. The system introduces a novel piezoelectric material-based eye blink sensor designed for wireless bionic control. It utilizes advanced PVDF / ZnO nanorods to create flexible sensors capable of passive eye movement detection and energy harvesting.

[0014] The system comprises a piezoelectric eye blink sensor module, a flexible substrate, a power management unit, a computing unit, and a wireless communication module. It operates autonomously as a self-powered node, reducing dependence on external power sources and improving practicality in various applications. The system offers a cost-effective solution for wireless bionic control and utilizes cutting-edge sensor technology to optimize functionality and reliability.

[0015] In one embodiment, the system's innovation lies in the seamless integration of advanced materials, circuit designs, and algorithms to maximize data processing efficiency and communication reliability. Expertise in nanomaterials, IoT communications, and circuit design is central to the implementation of this sophisticated solution. The system's versatility extends to applications such as robot control and human-computer interaction, where precise recognition of eye blink patterns plays a critical role. By prioritizing user comfort with skin-compatible materials and enabling sustainable energy harvesting, the system enhances the user experience and supports environmental sustainability goals.It represents a significant advancement in engineering and technology, driving innovation in healthcare, assistive technology and beyond, while ensuring scalability and seamless integration into existing IoT frameworks.

[0016] The system comprises a piezoelectric eyeblink sensor module, a flexible substrate, a power management unit, a computing unit, and a wireless communication module. The piezoelectric eyeblink sensor module contains PVDF / ZnO nanorods configured to generate an electrical signal in response to mechanical stress or stretching caused by eyelid movements. The flexible substrate on which the piezoelectric sensor module is mounted allows direct attachment to the skin. The power management unit is integrated into the piezoelectric sensor module, which serves to harvest energy from the generated electrical signals to operate the system autonomously. The computing unit, coupled to the sensor module and the power management unit, is configured to process the electrical signals to detect eyeblink patterns using an embedded algorithm.The wireless communication module connected to the computing unit is configured to transmit processed data to an external control unit for wireless bionic control applications. The system is designed to operate as a self-powered sensor node with minimal dependence on external power sources.

[0017] On the receiver side, the signals are also wirelessly captured and processed to control a robotic hand over a distance. The sensor operates according to the piezoelectric principle, generating a potential that correlates with the tension or load exerted by the eyelids. The sensor consists of a single sensor unit or an array of sensor units. These modules are designed to function independently or in combination within the node structure. The sensor node is also equipped with a power management unit and a computing unit to store data from the skin and transmit it to the control unit. The computing unit contains an algorithm for detecting the activity of the eye blink sensor module and transmitting control actions accordingly.Overall, the invention provides a small, wearable, flexible, self-powered eye blink sensor node for wireless control using the novel piezoelectric sensing material PVDF / ZnO nanorods.

[0018] First, the Ecoflex mold was prepared in a plastic Petri plate by combining Ecoflex parts A and B in a 1:1 ratio and then allowed to rest overnight. A conductive adhesive was prepared by ultrasonically mixing Ag paste (0.5 g) and single-walled CNTs (0.5 g) in isopropyl alcohol for 30 minutes. The Ag / CNT paste was applied to a 1 cm 2large area on top of the Ecoflex foil. A copper foil of the same size was then applied to the Ecoflex foil as a metal electrode, followed by another coating of Ag / CNT paste. A ZnO / PVDF / Ecoflex foil was then bonded to the Cu foil and dried for one hour. A layer of conductive paste (Ag / CNT) was then applied to the ZnO / PVDF / Ecoflex mold, and another Cu foil-based metal electrode was attached. The resulting Cu / CNT@Ag electrodes were then ready to transfer charge to the external circuit. Additionally, another layer of Ecoflex was applied to the component and left at ambient temperature for 6 hours, sandwiching the component / sensor between the Ecoflex layers.

Claims

[1] A novel piezoelectric material-based eye blink sensor system for wireless bionic control, comprising: a piezoelectric eye blink sensor module using PVDF / ZnO nanorods configured to generate an electrical signal in response to mechanical stress or stretching caused by eyelid movements; a flexible carrier material on which the piezoelectric sensor module is attached and which allows direct application to the skin; a power management unit integrated into the piezoelectric sensor module, which serves to extract energy from the generated electrical signals to operate the system autonomously; a computing unit coupled to the sensor module and the power management unit, configured to process the electrical signals to detect eye blink patterns using an embedded algorithm; a wireless communication module connected to the computing unit and configured to transmit processed data to an external control unit for wireless bionic control applications; The system is designed to operate as a self-sufficient sensor node with minimal dependence on external energy sources. [2] The system of claim 1, wherein the piezoelectric eye blink sensor module comprises an array of sensor units to improve sensitivity and accuracy in detecting eyelid movements. [3] The system of claim 1, wherein the flexible substrate is made of Ecoflex material to ensure comfort and biocompatibility during prolonged wear on the skin. [4] The system of claim 1, wherein the power management unit includes a power collection circuit capable of storing the collected power for later use by the computing unit and the wireless communication module. [5] The system of claim 1, wherein the wireless communication module uses Bluetooth Low Energy (BLE) or the ESP32 protocol for efficient and power-saving data transmission. [6] The system of claim 1, wherein the piezoelectric sensor module generates a maximum output voltage of 20 V in response to eyelid movements. [7] The system of claim 1, wherein the energy harvesting unit is capable of generating a minimum output current of 150nA.