Next Article in Journal
Effects of NMES Combined with Water-Based Resistance Training on Muscle Coordination in Freestyle Kick Movement
Next Article in Special Issue
Raman Spectroscopy for Monitoring NOx and N2O in Combustion Products
Previous Article in Journal
Effects of NMES Combined with Resistance Training Using Underwater Surface EMG Sensors on Neuromuscular Activation of Breaststroke Technique in Breaststroke Athletes: Analysis of Non-Negative Matrix Muscle Synergy
Previous Article in Special Issue
Photoacoustic Spectroscopy-Based Detection for Identifying the Occurrence and Location of Laser-Induced Damage Using a Laser Doppler Vibrometer
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Article

Acoustic Signatures in Laser-Induced Plasmas for Detection of Explosives in Traces

1
Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Laboratory NUC-TECFIS-DIM, Via Enrico Fermi 45, 00044 Frascati, Italy
2
Institute of Physics Belgrade, University of Belgrade, 11080 Belgrade, Serbia
3
Italian National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Laboratory NUC-FUSEN-TEN, Via Enrico Fermi 45, 00044 Frascati, Italy
4
Fraunhofer Institute for Chemical Technology ICT, Energetic Materials Department, Joseph-von-Fraunhofer-Str. 7, 76327 Pfinztal, Germany
5
Department of Industrial Engineering, University of Rome Tor Vergata, Via del Politecnico 1, 00133 Roma, Italy
*
Author to whom correspondence should be addressed.
Sensors 2026, 26(2), 672; https://doi.org/10.3390/s26020672
Submission received: 17 December 2025 / Revised: 9 January 2026 / Accepted: 17 January 2026 / Published: 20 January 2026
(This article belongs to the Special Issue Laser and Spectroscopy for Sensing Applications)

Abstract

In this work we report the results of analysis of the acoustic signal generated by the interaction of a nanosecond laser pulse (30 mJ, 1064 nm) with various residues placed on a silica wafer. The signal was captured by a unidirectional microphone placed 30 mm from the laser-generated plasma. The examined sample classes, other than the clean wafer, included particles from soils and rocks, carbonates, nitro precursors, ash, coal, smeared diesel, and particles of explosives. We tested three types of explosives, namely PETN, RDX, and HMX, having different origins. For the explosives, the acoustic signal showed a faster rise, larger amplitude, different width, and attenuation compared with the other sample classes. By subtracting the acoustic signal from the wafer at the same position, obtained after four cleaning laser pulses, the contribution of echoes was eliminated and true differences between the residue and substrate became evident. Through four different features in the subtracted signal, it was possible to classify explosives without the presence of false positives; the estimated limit of detection was 15 ng, 9.6 ng, and 18 ng for PETN, RDX, and HMX, respectively, where the mass was extrapolated from nano-printed samples and LIBS spectra acquired simultaneously. Furthermore, HMX was distinguished from the other two explosives in 90% of the cases; diesel and coal were also recognized. We also found that explosives deposited through wet transfer behaved as inert substances for the tested masses up to 30 ng.
Keywords: explosives; traces; laser; acoustic; LIBS; detection; forensic; sensitive; limit of detection explosives; traces; laser; acoustic; LIBS; detection; forensic; sensitive; limit of detection

Share and Cite

MDPI and ACS Style

Lazic, V.; Stankov, B.; Andreoli, F.; Pistilli, M.; Menicucci, I.; Ulrich, C.; Schnürer, F.; Chirico, R.; Gaudio, P. Acoustic Signatures in Laser-Induced Plasmas for Detection of Explosives in Traces. Sensors 2026, 26, 672. https://doi.org/10.3390/s26020672

AMA Style

Lazic V, Stankov B, Andreoli F, Pistilli M, Menicucci I, Ulrich C, Schnürer F, Chirico R, Gaudio P. Acoustic Signatures in Laser-Induced Plasmas for Detection of Explosives in Traces. Sensors. 2026; 26(2):672. https://doi.org/10.3390/s26020672

Chicago/Turabian Style

Lazic, Violeta, Biljana Stankov, Fabrizio Andreoli, Marco Pistilli, Ivano Menicucci, Christian Ulrich, Frank Schnürer, Roberto Chirico, and Pasqualino Gaudio. 2026. "Acoustic Signatures in Laser-Induced Plasmas for Detection of Explosives in Traces" Sensors 26, no. 2: 672. https://doi.org/10.3390/s26020672

APA Style

Lazic, V., Stankov, B., Andreoli, F., Pistilli, M., Menicucci, I., Ulrich, C., Schnürer, F., Chirico, R., & Gaudio, P. (2026). Acoustic Signatures in Laser-Induced Plasmas for Detection of Explosives in Traces. Sensors, 26(2), 672. https://doi.org/10.3390/s26020672

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Metrics

Back to TopTop