[2511.22893] Switching-time bioprocess control with pulse-width-modulated optogenetics

Electrical Engineering and Systems Science > Systems and Control arXiv:2511.22893 (eess) [Submitted on 28 Nov 2025 (v1), last revised 7 May 2026 (this version, v2)] Title:Switching-time bioprocess control with pulse-width-modulated optogenetics Authors:Sebastián Espinel-Ríos View a PDF of the paper titled Switching-time bioprocess control with pulse-width-modulated optogenetics, by Sebasti\'an Espinel-R\'ios View PDF HTML (experimental) Abstract:Biotechnology can benefit from dynamic control to improve production efficiency. In this context, optogenetics enables modulation of gene expression using light as an external input, allowing fine-tuning of protein levels to unlock dynamic metabolic control and regulation of cell growth. Optogenetic systems can be actuated by light intensity. However, relying solely on intensity-driven control (i.e., signal amplitude) may fail to properly tune optogenetic bioprocesses when the dose-response relationship (i.e., light intensity versus gene-expression strength) is steep. In these cases, tunability is effectively constrained to either fully active or fully repressed gene expression, with little intermediate regulation. Pulse-width modulation can alleviate this issue by alternating between fully ON and OFF light intensity within forcing periods, thereby smoothing the average response and enhancing process controllability. Optimizing pulse-width-modulated optogenetics entails a switching-time optimal control problem with a binary input o...