Application Cases

Introduction

Al-based bioelectrolyte batteries represent a promising power-supply solution for wearable electronics, implantable devices and self-powered biosensors, since biofluids such as human sweat and tears can serve as biocompatible, readily-available electrolytes.

Nevertheless, their real-world deployment is greatly hindered by slow interfacial mass transfer and sluggish electrode reaction kinetics within bioelectrolyte systems.Conventional strategies relying on advanced catalyst materials or sophisticated electrode structures usually suffer from high fabrication cost, complex manufacturing procedures and insufficient longterm stability, which creates an urgent demand for effective physicalfield catalytic approaches to boost the output performance of biocompatible aluminium-based power sources.

The experiments reported in this paper target the above-mentioned bottlenecks for bio-friendly miniature power supplies.

An integrated ultrasonic liquid-phase catalysis strategy is proposed and validated through prototype tests, electrochemical characterisation and finite-element simulations.By taking advantage of synergistic effects including acoustic pressure, acoustic streaming and ultrasonic stirring, the assembled battery achieves remarkable enhancement in peak output power under multiple bioelectrolyte environments, including artificial sweat that mimics real human sweat composition.These experimental findings verify that ultrasonic physical catalysis can effectively mitigate interfacial mass-transport limitations, offering a feasible technical route toward practical selfpowered biosensors, wearable medical electronics and other green biointegrated electronic systems.

Research Direction

Ultrasonic Electrochemistry

Experimental objective

Aluminum-based batteries have shown great attraction in integration with biological electrolytes such as sweat and tears, making it possible to develop portable and biocompatible power sources.However, their practical application is severely constrained by slow mass transfer and reaction kinetics at the catalytic electrode interface.In this study, we propose a compact ultrasonic catalytic aluminum-based bio-electrolyte battery to overcome this limitation.The performance enhancement mechanism originates from the synergistic effects of acoustic pressure, acoustic streaming, and ultrasonic agitation, which collectively accelerate interfacial mass transfer and electrode reaction kinetics.

Testing equipment

ATA-4052, signal generator, oscilloscope, electrochemical workstation, current probe, voltage probe.

Experimental process

1.Design and fabrication of the ultrasonic liquid-phase catalytic aluminum-based bio-electrolyte battery：

The ultrasonic liquid-phase catalytic aluminum-based battery consists of an ultrasonic transducer (HNC-4AS-2565, resonant frequency 65.1 kHz) and an aluminum-based battery unit.The battery substrate uses a glass substrate with dimensions of 25 x 2.7 mm.A semicircular aluminum electrode is used as the anode and a platinum electrode as the cathode.The diameter and thickness of both electrodes are φ 20.5 mm and 0.06 mm, respectively, and the spacing between the electrodes is 1 mm.

2.Vibration characteristic characterization — vibration mode and frequency determination：

A laser Doppler vibrometer (LDV, PSV-300F-B) was used to characterize the vibration modes on the glass substrate surface, confirming that the system vibration mode is piston-type vertical vibration with a resonant frequency of 65.12 kHz.Impedance analysis of the battery system was performed using an impedance analyzer (4294A), and the measured resonant frequency was 65.25 kHz.The test results are in good agreement with the LDV results, verifying the accuracy of the system.

3.Ultrasonic driving system

A signal generator (DG922pro) was used to control the power amplifier (ATA-4052) to provide the driving signal for the ultrasonic transducer.

Meanwhile, an oscilloscope (DHO1074) was used to monitor the ultrasonic driving voltage and driving current signals of the battery in real time, ensuring that the ultrasonic transducer operates in a resonant state.

4.Electrochemical performance characterization：

An electrochemical workstation (CHI 760E) was used to measure the polarization curves of the battery via the potentiostatic step method.The test voltage was gradually decreased from 0.55 V to 0 V in steps of 0.05 V.Each voltage step was maintained for 30 s, and the average stable current value of the second half (15–30 s) was taken as the discharge current at that voltage, from which the I-V and I-P curves were plotted.Electrochemical impedance spectroscopy tests were performed at an open-circuit voltage of 0.55 V, with a frequency range of 100 kHz to 0.1 Hz and an AC amplitude of 5 mV, to characterize the interfacial impedance of the battery system.

Figure1 (a) Structure diagram to show the integration between the ultrasonic transducer and the battery unit.

(b) Structure diagram of the ABBB.

(c) Dimensions of the ultrasound-assisted ABBB.

(d) Prototype photo.

Figure2 Experimental setup for performance measurement of the ultrasound-catalyzed ABBB.

Experimental results

When The polarization curves and power curves of the ultrasonic liquid-phase catalytic aluminum-based battery were investigated under different ultrasonic vibration velocities (142.5, 297.8, 364.7, 427.3, and 459.3 mm/s).For electrolytes of sodium chloride, glucose, and lactic acid, the peak output power of the battery showed a monotonically increasing trend with increasing vibration velocity.Specifically, for the NaCl (glucose and lactic acid) electrolytes, the peak power increased from 51.37 mW (2.252 mW and 1.820 mW) at 142.5 mm/s to 146.754 mW (5.879 mW and 10.838 mW) at 459.3 mm/s.

Compared with the case without ultrasonic liquid-phase catalysis (US OFF), for the NaCl (glucose and lactic acid) electrolytes, the peak power was enhanced by 2.4 times (1.5 times and 1.7 times), 3.8 times (2.3 times and 2.8 times), 5.4 times (2.9 times and 5.5 times), 6.7 times (3.6 times and 7.5 times), and 6.9 times (3.9 times and 9.8 times), respectively.

Figure3 Principle schematic of the ABBB catalyzed by ultrasound.

Figure4 Discharge performance of ABBB under different ultrasonic vibration velocities in NaCl, glucose, and lactate bioelectrolytes.

(a), (b) & (c) Polarization and power curves.

(d), (e) & (c) Peak power versus vibration velocity.

The effectiveness of the amplifier in this experiment

Used to drive the ultrasonic transducer.

Application fields

Wearable electronics, selfpowered biosensors, biointegrated electronics, implantable medical devices, aluminiumbased battery, bioelectrolyte, ultrasonic liquidphase catalysis.