Acoustically shaped laser: A machining tool for Industry 4.0

Abstract

The high versatility of laser direct-write (LDW) systems offers remarkable opportunities for Industry 4.0. However, the inherent serial nature of LDW systems can seriously constrain manufacturing throughput and, consequently, the industrial scalability of this technology. Here we present a method to parallelise LDWs by using acoustically shaped laser light. We use an acousto-optofluidic (AOF) cavity to generate acoustic waves in a liquid, causing periodic modulations of its refractive index. Such an acoustically controlled optical medium diffracts the incident laser beam into multiple beamlets that, operating in parallel, result in enhanced processing throughput. In addition, the beamlets can interfere mutually, generating an intensity pattern suitable for processing an entire area with a single irradiation. By controlling the amplitude, frequency, and phase of the acoustic waves, customised patterns can be directly engraved into different materials (silicon, chromium, and epoxy) of industrial interest. The integration of the AOF technology into an LDW system, connected to a wired-network, results into a cyber-physical system (CPS) for advanced and high-throughput laser manufacturing. A proof of concept for the computational ability of the CPS is given by monitoring the fidelity between a physical laser-ablated pattern and its digital avatar. As our results demonstrate, the AOF technology can broaden the usage of lasers as machine tools for industry 4.0.