Fig. 1. Micro/nanorobots based on direct optical manipulation. Fundamental principles of optical tweezer manipulation^[18], where (a1) trapping by optical force, (a2) optical scattering force, and (a3) optical gradient force; (b) conceptual diagram of a living-cell bio-microrobot constructed by an optical tweezer-trapped rotating microalgaecell^[19]; (c) schematic of opto-hydrodynamic bio-micromotor tweezers^[20]; (d) non-contact trapping and transport of a motile Escherichia coli by bio-micromotor tweezers^[20]; (e) schematic of the structure of optoelectronic tweezers (OETs) ^[21]; (f) schematic of flexible assembly of micro-spirulina via OETs^[22]; (g) bright-field microscope images depicting the loading, transportation, and delivery of particles by cogwheel-shaped microrobot^[23]

Fig. 2. Bio-optically driven micro/nanorobots. (a) Scheme of typical structure of a diflagellate green algae with bio-phototaxis^[19]; (b) phototaxis-driven microalgae robot with controlled navigation in microfluidic channels based on diflagellate green algae^[27]; (c) schematic illustration of phototaxis, motion and deformation of light-controlled soft microrobots based on microalga Euglena gracilis^[28]; (d) microscopic images showing a soft microrobot navigating through a curved channel under light guidance^[28]; (e) scheme of a miniaturized capsule microrobot based on light-responsive probiotic bacteria^[29]

Fig. 3. Photothermal-driven micro/nanorobots. (a) Simulated temperature field and (b) simulated thermo-osmotic flow under the NIR light irradiation around a photothermal-responsive microrobot^[32]; (c) schematic illustration of the mechanism of self-thermophoresis of the photothermal-driven microrobot after absorbing heat^[32]; photothermal-driven SiO₂/Au Janus nanorobots^[33], where (d1) fabrication scheme of the SiO₂/Au Janus nanorobots, (d2) time-lapsed microscopic images of the on/off motion of nanorobots; (e) schematic diagram of a swarm of Fe₃O₄-based microrobots driven by the photothermal-induced hydrodynamic drag^[34]; gear-shaped photothermal-driven microrobots^[35], where (f1) SEM image of a gear-shaped microrobot, (f2) simulated temperature field under blue light irradiation around the gear-shaped microrobot

Fig. 4. Light-induced chemically reactive micro/nanorobots. (a) Schematic illustration of the actuation mechanism and (b) experimental demonstration of positive and negative phototaxis for self-electrophoretic nanorobots driven by photocatalytic reactions^[42]; (c) schematic representation of the motion mechanism for electrolyte diffusiophoresis-driven microrobots^[44]; (d) scheme of bubble propulsion-driven microrobots^[45]

Fig. 5. Photoinduced deformation-actuated microrobots. (a) Schematic diagrams and experimental images of UV light-driven locomotion for wheel-shaped and spring-like microrobots based on LCE bilayer films^[48]; (b) experimental images of AC-LCE-based helical spring soft microrobots performing underwater tasks, including annular contraction and grasping operations^[49]

Fig. 6. Optical tweezer-actuated micro/nanorobots for precise drug delivery. (a1) Schematic illustration and (a2) experimental images of controllable disruption of biological aggregates by algae micromotors^[19]; (b1) schematic illustration of nano-biothreat removal using OHD and (b2) fluorescence images showing the removal of Escherichia coli in cultured cells by an OHD array^[51]; (c1) schematic diagram and (c2) experimental diagram of light-armed nitric oxide-releasing micromotor for the degradation and thrombus clearance in blood vessels in vivo^[52]

Fig. 7. Application of light-controlled micro/nanorobots in disease diagnosis and biosensing. (a) Schematic diagram of light-controlled nanorobots for precise detection of circulating tumor cells^[53]; (b) schematic illustration of the light-controlled robotic microsensor for biomarker detection in vivo^[54]; (c) schematic diagram showing optical assembly of the RBC waveguide microrobots inside the blood vessels of a zebrafish^[55]; (d) experimental diagram of in situ detection of blood pH values through biological waveguides assembled with RBCs of different morphologies^[55]

Fig. 8. Light-controlled micro/nanorobots for precise drug delivery. (a) Light-propelled stomatocyte nanomotors for efficient intracellular transport^[58]; (b1) schematic illustration and (b2) experimental images of swarm formation at the water-oil interface by light-induced CMF^[59]; (c) dual-driven nanorobots by photothermal and NO gas for enhanced intestinal mucus and epithelial penetration^[60]; (d) nanorobots driven by red light and propulsive gas to deliver anticancer agents into deep tumors^[61]

Fig. 9. Application of light-controlled micro/nanorobots in minimally invasive surgery and precision treatment. (a) Microrobotic laser steering device for minimally invasive surgery^[62]; (b) schematic illustration of the photothermal propulsion nanomotors enhancing PPT and chemotherapy^[63]; (c) schematic illustration of tumor PDT using soft bio-microrobot based on microalga Euglena gracilis^[28]; (d) scheme showing light-driven algae microrobots enhancing PDT through precise oxygen delivery^[64]; (e) schematic illustration of precise neural stimulation using optomechnical bio-dart nanorobots^[65]