Green energy from working surfaces: a contact electrification–enabled data theft protection and monitoring smart table

Highlights

• Triboelectric effect is incorporated as a smart feature in the table which triggers an alarm upon intruder touches the desk.

• The triboelectric nanogenerator (TENG) works in the single electrode contact-separation mode as well as in sliding mode.

• Kapton film is the main triboelectric layer and the material on apparels, hand-skin acts as opposite triboelectric layer.

• The fabricated TENG coupled with Arduino board is placed to the table which triggers an alarm upon unauthorized access.

Abstract

Data theft from the desktop system using devices capable of storing data is a serious problem that causes great harm to an individual or a company. It is essential to excogitate a way to reduce the problem. The triboelectric nanogenerator (TENG), recently introduced as a light-weight, easy-to-design energy harvester, works on the coupling of electromagnetic induction and contact electrification. In this work, a TENG is used to incorporate a smart feature in the table which triggers an alarm if an intruder is using the desk. The TENG works in the single-electrode contact-separation mode and in the sliding mode. The Kapton backed by aluminum is used as active triboelectric layers while the material on apparels or hand skin acts as opposite triboelectric material. The device is systematically studied for its electrical performance using materials such as jeans, cotton, paper, etc. The device gives the highest output voltage and current of ~200 V and 2.2 μA in case of paper. Finally, a smart table is demonstrated using the as-fabricated TENG coupled with the Arduino board which triggers an alarm if a person is accessing the desk. This work can extend the application of the TENG for the development of smart furnitures.

Introduction

Data theft is a significant problem faced in the digital world. Data theft can occur through desktops, servers, etc. The easiest way of data theft is to copy the data in the storing devices such as USB flash drives, hard disk, and so on. The companies make great efforts to preserve their data that may contain confidential or copyrighted information, as it is essential for developing contacts. The tech giant such as yahoo also faced a data breach incident in the year 2013. The data breach from the desktop computer using external storage can be reduced with simple measurements. In recent years, nanogenerators based on piezoelectric and triboelectric effect are widely reported as promising energy sources for harvesting mechanical energy from various sources viz. sound, human motion, wind, water, etc [[1], [2], [3], [4], [5], [6], [7], [8]]. The piezoelectric nanogenerators have a drawback of being complex, high brittleness, and high manufacturing cost [9,10]. The triboelectric nanogenerator (TENG) has been introduced as an efficient energy harvester, and it works on the physics of contact electrification and electrostatic induction [11].

The TENG is a simple and straight-forward solution to harness the waste mechanical energy [12]. The TENG offers the advantage of being light-weight, easy to fabricate, and cheap [6]. However, triboelectrification is not clearly understood yet, but few attempts were made from ion transfer [13], charge transfer [14,15], bonding of radicals [16,17], etc. The output of the TENG can be tuned by selecting materials of distinct polarity. Furthermore, the TENG operates in four different modes: viz. vertical contact-separation mode, single-electrode mode, sliding mode, and freestanding mode [18,19]. The different modes of the TENG offer excellent flexibility for the application. The TENG is widely reported in various applications such as scavenging biomechanical energy [20,21], water-wave energy harvesting [22], sports applications [23], physical sensors [24] (temperature [25], vibration [26], and pressure [27]), chemical sensors (humidity [28], phenol detection [29], and benzene monitoring [30]), cell stimulation, drug delivery, implantable devices [[31], [32], [33]], biomedical systems [34], and air filters [30,[35], [36], [37]].

Herein, the present work reports a smart table by directly integrating the TENG on the table. The smart table triboelectric nanogenerator (ST-TENG) works in the single-electrode mode, with operation by vertical contact and separation. The device fabrication adopts a simple and cost-effective approach by using commercially available materials. The Kapton film and contact materials such as polyethylene, jeans, cotton, and paper work as an active material for the ST-TENG. The ST-TENG gives an output of 200 V and 2.2 μA in case of paper as a contact material with an excellent output power of 1000 μW with a load resistance of 30 MΩ. Finally, we demonstrated a self-powered table security system by integrating the TENG with Arduino Uno for triggering the alarm and warning message when an intruder or unknown person touches the table. The warning message is shown on the computer screen with a light-emitting diode (LED) glow and a buzzer beep. The proposed work opens up the new avenues toward self-powered systems in smart security, data theft, and internet of things.