Battery-less Device Research Articles

Adaptive Transmissions for Batteryless Periodic Sensing

Batteryless, self-sustaining embedded sensing devices are key enablers for scalable and long-term operations of Internet of Things (IoT) applications. While advancements in both energy harvesting and intermittent computing have helped pave the way for building such batteryless IoT devices, a present challenge is a system design that can utilize intermittent energy to meet data requirements from IoT applications. In this paper, we take the requirement of periodic data sensing and describe the hardware and software of a batteryless IoT device with its model, design, implementation, and evaluation. A key finding is that, by estimating the non-linear hardware charging and discharging time, the device software can make scheduling decisions that both maintain the selected sensing period and improve transmission goodput. A hardware–software prototype was implemented using an MSP430 development board and LoRa radio communication technology. The proposed design was empirically compared with one that does not consider the non-linear hardware characteristics. The result of the experiments illustrated the nuances of the batteryless device design and implementation, and it demonstrated that the proposed design can cover a wider range of feasible sensing rates, which reduces the restriction on this parameter choice. It was further demonstrated that, under an intermittent supply of power, the proposed design could still keep the device functioning as required.

MPI: Memory Protection for Intermittent Computing

Batteryless devices harvest energy from sporadic ambient sources, enabling a wide range of long-lived, stand-alone, and environmentally-friendly sustainable applications. Software on these devices operates intermittently due to frequent power failures. Each power failure leads the device to lose its computational state that hinders the forward progress of computation and memory consistency. One solution to remedy this situation is to pair programs with checkpoints to save a snapshot of the intermediate program state to non-volatile memory before a power loss. Due to the lack of protection mechanisms in the state-of-the-art intermittent systems, checkpoints can be altered either by programmer errors or deliberately by an attacker. This situation leads to catastrophic effects since the program execution might be corrupted, and in turn, the device might malfunction. In this paper, we propose MPI, a memory protection mechanism for intermittent computing systems. In particular, MPI is a minimal intermittent-compliant trusted computing base acting as a hypervisor that fully manages and protects the underlying memory of a batteryless device. MPI enables a reliable and secure generation and restoration of checkpoints, maintaining their integrity and access control in the presence of remote software-based attacks without trusting the user program or requiring programmer intervention. Notable is that MPI neither requires hardware modifications nor depends on hardware features that might not exist in all batteryless platforms. Our experiments on a real batteryless platform show that MPI provides stronger security guarantees compared to the state-of-the-art approaches, with a comparable time and energy overhead.

Controlled transdermal drug delivery using a wireless magnetic microneedle patch: Preclinical device development

This paper presents a magnetic polymer-driven transdermal drug delivery system. Transdermal drug delivery has several advantages over oral and hypodermic administration, including painless delivery and avoiding first-pass metabolism. In this study, magnetic polymer composites (MPCs) and inductive sensing principles were utilized as the key actuator and sensor technologies to enable controlled drug release through a single hollow microneedle. The proposed system is capable of drug dispensing and dosage sensing, without the need for on-board electronics or batteries. Through experimental testing, the battery-less device demonstrated controllable zero-order and pulsatile drug release profiles, and was able to pierce and inject solution into excised human skin. This novel wireless pumping system provides the capability to control the volume dispensed for transdermal delivery in a compact, wearable form factor.

Implantable batteryless device for on-demand and pulsatile insulin administration

Many implantable systems have been designed for long-term, pulsatile delivery of insulin, but the lifetime of these devices is limited by the need for battery replacement and consequent replacement surgery. Here we propose a batteryless, fully implantable insulin pump that can be actuated by a magnetic field. The pump is prepared by simple-assembly of magnets and constituent units and comprises a drug reservoir and actuator equipped with a plunger and barrel, each assembled with a magnet. The plunger moves to noninvasively infuse insulin only when a magnetic field is applied on the exterior surface of the body. Here we show that the dose is easily controlled by varying the number of magnet applications. Also, pump implantation in diabetic rats results in profiles of insulin concentration and decreased blood glucose levels similar to those observed in rats treated with conventional subcutaneous insulin injections.

Improved Battery-Less Augmented RFID Tag: Application on Ambient Sensing and Control

In this letter, an improved version of a recently published battery-less augmented radio frequency identification device enabling a tag-reader cooperative approach is presented. Based on a specifically designed physical layer implementing a logical communication procedure over low-level reader protocol, the device is now capable to react to the reader solicitations by reasoning, asking for extra info, taking autonomous decisions, piloting actuators, and generating alerts. Tests performed in the building automation context demonstrate the capability of the proposed device of reasoning jointly with the reader and changing its behavior according to logical and physical events occurring in the surrounding environment.

Device and operation mechanism for non-beacon IEEE802.15.4/Zigbee nodes running on harvested energy

The power supply is one of the main constraints when operating Wireless Sensor Networks (WSN). The most obvious energy source for a WSN node is a rechargeable or non-rechargeable battery. Batteries seriously limit WSNs usage and are associated to the increasing cost of large networks. Low cost networks will be achieved when battery consumption becomes substantially reduced or eliminated. Within this scope, powering WSN devices using mains power, is not an advantage since node installation requires complex and time consuming actions. Replacing batteries is therefore an important topic even in environments with mains power availability. In this paper, a battery-less device running an IEEE802.15.4/Zigbee protocol stack on harvested energy is proposed. Its operation mechanism and required software adaptation to sustain this complex protocol are described. The protocol compliant node uses a contact-less scavenger system that is able to power a WSN node from mains power lines thus providing an inexpensive and easily installable device even for non-skilled users.

Printed Decoupled Dual-Antenna Array On-Package for Small Wirelessly Powered Battery-Less Device

A printed compact antenna array for small wirelessly powered device operating at 900 MHz is proposed. The prototype is developed by printing antenna pattern on a 0.1-mm-thick flexible substrate and folding the printed sheet into a rectangular volume measuring 35 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times\,$</tex> </formula> 56 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\,\times\,$</tex> </formula> 12 mm <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$^3$</tex> </formula> . The edge-to-edge distance between array elements is only <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$0.078~\lambda$</tex></formula> . An isolation structure is added to minimize the coupling between the elements. Measurement results show a <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$-$</tex> </formula> 27-dB minimum coupling between the elements, which yields significant gain improvement up to 3.6 dB and radiation efficiency improvement up to 28% over the design without isolation structure. When integrated with rectifier circuits, the proposed design also demonstrates superior performance by generating more dc power. The results have shown the proposed work to be a feasible solution of implementing antenna array for small device to enhance of RF power receiving capability with high compactness.