Thèse Conception Fabrication par Impression 4D Contrôle et Caractérisation de Microrobots Souples H/F - Doctorat.Gouv.Fr

Établissement : Université Marie et Louis Pasteur École doctorale : SPIM - Sciences Physiques pour l'Ingénieur et Microtechniques Laboratoire de recherche : Franche Comté Electronique Mécanique Thermique et Optique - Sciences et Technologies Direction de la thèse : Cédric CLEVY ORCID 0000000278814245 Début de la thèse : 2026-10-01 Date limite de candidature : 2026-05-27T23:59:59 Cette thèse de doctorat vise à développer une nouvelle génération de microrobots souples pour relever les grands défis de la santé et de la fabrication avancée. Elle exploite des technologies de pointe telles que l'impression 4D et la stéréolithographie à deux photons pour créer des microrobots 3D intelligents et réactifs. Ces microrobots photoactivés, intégrés à l'extrémité de fibres optiques, permettront une actionnement précis et à plusieurs degrés de liberté dans des espaces extrêmement restreints. Le doctorant recruté participera activement au nouveau réseau national de recherche en robotique miniature (PEPR Miniro, 2025-2032) et aura un accès complet aux équipements et installations, notamment ceux du CMNR (Centre de micro et nano robotique - Infrastructure nationale pour la recherche de pointe en robotique) et de la plateforme technologique de salles blanches Mimento (Réseau national des grands pôles technologiques pour la recherche fondamentale). To meet growing needs in the fields of healthcare and manufacturing, microrobotics brings highly original and powerful solutions but is expected to undergo a paradigm shift by combining dexterity, compactness, workspace, and precision [SLY16][MKB25][JCO25]. Several promising approaches are being investigated including 4D printing i.e. 3D printed structures that can deform with time [JMC21][KJB23][LLH25], folding of active planar substrates [BWR21][LEI23] or planar smart surfaces [VJ22][NPH25]. In this context, a highly promising approach has recently been developed through collaboration between the FEMTO-ST Institute (the AS2M and MN2S departments) and IS2M. It involves using Two-Photon Stereolithography (TPS) to fabricate micro-nano-robots made of photo-activated materials mounted at the tips of optical fibers. The main goal is to design the first generation of microrobots by combining complex 3D structures with photo-thermo-multi-reactive polymers [SS20][ABR21] and can efficiently interact with their working environment (ability to control force, achieve tasks such as manipulation) [ABR24]. Such robots do not yet exist and would enable the resolution of numerous practical problems, whether in the field of minimally invasive surgery, cell manipulation, or the manipulation and assembly of industrial components for which such tools do not yet exist but would possess unique capabilities. In this scope, Roberval also recently demonstrated the capability to actuate and sense by lasers (fibers and steering mirrors) at small scales covering modeling and control aspects with success which will strongly contribute to the proposed approach [MHD24][NPH25].
This PhD thesis builds on these very recent works that led to the development of a thermosensitive polymer (based on PNIPAM) with properties that are particularly disruptive for the field of microrobotics compared to commercially available polymers, such as its ability to generate large motions and the possibility of remote activation via a laser beam. A 4D printing process has also been developed to successfully fabricate actuators from this polymer, as well as to create multi-material structures combining these actuators with 3D-printed passive components. These initial proof-of-concepts have also been subjected to multiphysics modeling and experimental quantification of their performance. The initial results obtained as part of the national ANR PNanoBot project (see Figure 1) are extremely promising [SBC25].
Building on these unique proof-of-concepts, the main objectives of this thesis are to propose original designs based on 4D-priting for various microrobots types-that is, robots incorporating multiple actuators and a passive mechanical structure. Several robotic architectures will be studied, starting with basic building blocks, as well as serial and parallel robots. The integration of these robots at the tip of a multi-core optical fiber will be of key interest to enable the localized and multi-DoF (Degrees of Freedom) actuation in very tiny workspaces. Indeed, part of the work will involve doping the actuators with metal particles (to absorb energy from a laser beam), which will allow for the selective heating of each actuator. Key influential parameters of the laser/matter interaction will be studied such as the wavelength, power, etc. The thesis will include proposing designs, finite element simulation of their behavior (multiphysics simulation such as COMSOL Multiphysics mainly), 3D printing of several robots, and characterizing their performance using an existing experimental platform that will need to be adapted and improved for this purpose. The experimental work will require, in particular, familiarity with and mastery of all the tools on the dedicated test bench (control of positioning axes, image acquisition, etc.). The ultimate goal of the thesis will be to build the first sub-millimeter-scale robots and demonstrate their potential through illustrative videos and experimental data quantifying their performance (working range, repeatability, path and trajectory tracking, execution of a manipulation task, etc.). This last objective will thus include modelling of the behavior and control.

Nous recherchons un candidat très motivé, capable de travailler en équipe, ouvert d'esprit et orienté résultats. Les candidats doivent posséder les compétences suivantes :
- Master en génie mécanique, mécatronique, robotique ou équivalent, avec mention, couvrant les aspects théoriques/méthodologiques et expérimentaux.
- Solide expérience en modélisation de systèmes multiphysiques, automatismes, robotique, matériaux souples et fabrication (micro-usinage).
- Maîtrise de Matlab, Python ou C++, des logiciels de CAO et de la méthode des éléments finis.
- Intérêt et/ou expérience en investigations/validations expérimentales.
- Des compétences supplémentaires en vision par ordinateur et optique (lasers) seraient un atout.
Les candidats doivent maîtriser l'anglais. La maîtrise du français serait un avantage.