Project results
An overview of the main data, reports, deliverables, and any other know-how developed or produced in the course of the activities performed within the artMAP project.
PHASE 2 OF THE PROJECT | JAN - Dec 2023
Summary report
The key outcomes of this second stage of the project include (1) completion of the new LIF experimental setup, (2) development of a new software interface and (3) design and development of a specialized LIF database. With the completion of this stage, the first two objectives of the artMAP project have been achieved.
The new software interface
Building on the requirements set in the project’s first phase, a user-friendly software interface has been developed, tested and optimized. The application, developed in LabVIEW (Laboratory Virtual Instrument Engineering Workbench), allows for the acquisition of spectral data and the generation of 2D scanning maps. The scanning module of the application is in the final stage of development, with completion and optimization expected early next year.
Wall painting replicas
A series of wall paiting replicas were produced (both a fresco as well as a secco) – a combination of a lime-based substrate and a variety of painting materials. Each replica was composed of four sectors painted with three variable parameters: pigments, binders, and phase of application. The selected painting materials cover a wide range of organic binders and mineral pigments, commonly found in ancient mural paintings.
Development of a LIF spectral library
Over 50 reference samples were investigated via LIF spectroscopy, with the 266 nm laser excitation wavelength. In accordance with the FAIR guiding principles, all reference LIF spectra acquired by the end of the project will be integrated into the INFRA-ART Spectral Library, an open-access database of art-related materials.
Stage 2 | Progress report
The hardware architecture of the new LIF scanning system has been completed. Harmonics 2 (532 nm), 3 (355 nm), and 4 (266 nm) have been acquired, along with an optical attenuator for the Nd:YAG Litron Nano S 60-30 laser system. A custom-made dual-axis galvanometer scan head system has also been developed and integrated.
A new software interface compatible with the upgraded architecture has been developed, tested, and optimized. The application, created in the LabVIEW environment, enables both spectral data acquisition and mapping.
A specialized LIF spectral library has been developed. The library comprises at this moment over 50 reference samples that cover a wide range of organic binders and mineral pigments commonly found in ancient murals.
Following the FAIR guiding principles, all reference LIF spectra acquired by the end of the project will be incorporated into the INFRA-ART Spectral Library, an open-access data infrastructure for heritage science
In terms of sharing our research findings, we have published a comprehensive review article in the Chemosensors journal, on the current state-of-the-art of LIF applications within the cultural heritage field. Another article focused on the characterization of ancient organic residues has been published in an interdisciplinary journal, and two papers have been presented at TECHNART, and CSI XLIII respectively.
PHASE 1 OF THE PROJECT | Jul - Dec 2022
Summary report
The specific objectives of the first phase of the artMAP project were the upgrade of the existing LIF scanning system with a new laser source and the development of a new software interface. According to the working plan, within this first stage of the project, three tasks were carried out. The main results of this stage include (1) the design and development of the new LIF system, (2) the upgrade and preliminary testing of the new experimental LIF set-up (3), and the design of the new LIF software interface.
The new laser system
An ultra-compact, rugged, Q-Switched Nd:YAG Nano S laser from Litron was purchased. The Nano S laser is one of the smallest ‘end user’ laser system available on the market that offers flexibility to access all the wavelengths from 1064nm to 266nm by removing and re-combining the appropriate modular harmonic generation units. A motorized optical attenuator included within the configuration allows the user to vary the pulse energy remotely while also maintaining the temporal and spatial profiles of the beam. Our system was configured with a stable resonator that allows the user to alter parameters such as input energy and repetition rate with very little variation in beam quality.
Outline of the new scanning system
The LIF experimental set-up will be updated with a new scanning system. In place of the old two stepper motors which together weigh almost 4kg and use a single mirror, a very small scan head will be installed which uses two mirrors for scanning and comes with a dedicated control board. This upgrade will also require a different approach in terms of electronic communication with the scanning assembly. The entire optoelectronic architecture will undergo major changes, the goal being to perfectly adapt the LIF scanning system to the new laser unit and, on a secondary level, to miniaturize the LIF system as much as possible.
Design of a new software interface
Following the upgrade of the LIF set-up with a new laser source and with a new scan system, a new software interface compatible with the new architecture is required. The new software application will retain some of the core features of the old LabView interface, but will also include new functions in order to enhance the scanning performance.
Stage 1 | Progress report
An extensive literature review was conducted on the applications of Laser-induced fluorescence (LIF) spectroscopy in the field of heritage science. The information obtained on the topic will be used in an upcoming review paper.
Based on the literature survey and the comparative analysis of the various LIF systems employed for the characterization of painted surfaces, the key technical criteria were established.
Grounded on the key technical criteria identified an ultra-compact Q-Switched Nd:YAG laser system (Litron Nano S) was purchased. The system allows access to all harmonic wavelengths from 1064 nm to 266 nm.
The first laboratory tests were carried out with the new laser unit and the scanning components of the new experimental LIF set-up were outlined;
A new software interface compatible with the new hardware architecture has been designed. Development and implementation of this new software will be carried out in the next phase of the project.