Millimeter-scale soft continuum robots offer safety and adaptability in transluminal procedures due to their passive compliance, but this feature necessitates interactions with surrounding lumina, leading to potential medical risks and restricted mobility. Here, we introduce a millimeter-scale continuum robot, enabling apical extension while maintaining structural stability. Utilizing phase transition components, the robot executes cycles of tip-based elongation, steered accurately through programmable magnetic fields. Each motion cycle features a solid-like backbone for stability, and a liquid-like component for advancement, thereby enabling autonomous shaping without reliance on environmental interactions. Together with clinical imaging technologies, we demonstrate the capability of navigating through tortuous and fragile lumina to transport microsurgical tools. Once it reaches larger anatomical spaces such as stomach, it can morph into functional 3D structures that serve as surgical tools or sensing units, overcoming the constraints of initially narrow pathways. By leveraging this design paradigm, we anticipate enhanced safety, multi-functionality, and cooperative capabilities among millimeter-scale continuum robots, opening new avenues for transluminal robotic surgery.

In this paper, we present a method for conducting automated micromanipulation that uses a cantilevered micropipette probe (CMP), which is capable of high-sensitivity contact detection. A dynamic probing method is proposed to achieve highly precise and nondestructive micromanipulation with the slightly oscillating CMP (amplitude: ~5 nm, the 1$^{st}$ resonance mode). By measuring the frequency shift of the CMP in real time, this method not only can accurately control the contact force at the nanoNewton level, but also can determine whether a mass as small as several picograms (10$^{-12}$g) is successfully picked up or released. A microrobotic system with the top- and side-view microscopes is developed for adhesive microbonding through two cooperating CMPs. The effectiveness of the method is verified by conducting 3D manipulation of microbeads of diameters varying from 3 μm to 20 μm, assembling 2D and 3D structures with a sub-micrometer accuracy, attaching a microbead to an atomic force microscopy (AFM) probe for stiffness calibration, and fabricating a functional AFM probe by adhesively bonding a magnetic microbead to AFM cantilevers. The experimental results demonstrate the versatility and robustness of the developed method in the field of automated micromanipulation and adhesive microbonding.

This paper presents a method that combines a robust controller ( $H_\infty$ ) and an iterative learning controller (ILC) to control a low mechanical bandwidth nanopositioning stage for high-speed atomic force microscopy (AFM) imaging. In conventional scanning configurations, the imaging speed of a low-resonance frequency scanner is limited to a few Hz. However, the images obtained using the proposed method have no obvious anamorphosis with a scan speed of up to 80 Hz. This method uses a sinusoidal scanning mode in the fast-scan axis, which effectively reduces the mechanical vibration of the XY-scanner and improves the imaging bandwidth. In addition, a compact high-bandwidth Z-scanner configured with a symmetrical dual-actuator was developed to replace the Z-axis of the nanopositioning stage for high-speed tracking of the sample topography. To further improve the imaging performance, an ILC was designed to suppress the nonlinear behavior of piezoelectric and reduce the tracking error. In addition, a model-based $H_\infty$ was designed to reduce the measurement error and enhance the image quality. All algorithms and real-time control are implemented with a field-programmable gate array (FPGA) platform. The experimental results demonstrated that these configurations exhibit significant performance improvements by comparison with conventional scanning modes.

This paper presents a piconewton forcecontrolled magnetic microgripper (MMG) for microscale manipulation and characterization. The MMG consists of a cantilevered wrist force sensor and a magnetically driven double-finger gripper at the end. The manipulating force can be accurately detected by the wrist force sensor using an atomic force microscopy (AFM) optical lever. Moreover, the clamping force can be also precisely controlled by regulating the magnetic torque applied to the gripper fingers via the attached ferromagnetic beads. In addition, an AFM dynamic probing method was used for contact and clamping detection with the frequency shift of the oscillating MMG. The performance tests showed that the MMG has a gripping range of 0 to 17.4 μm; it allows for accurate clamping force loading with a resolution of 38 pN and detecting the grasping force with a resolution of 182 pN. The capability of the MMG was verified by conducting threedimensional manipulation of the microbeads Ø2-Ø16 μm with sub-micrometer accuracy and acting as an AFM colloid probe for fast mapping of the adhesion force. The proposed MMG is the first demonstration of a prototype capable of piconewton force-controlled micro-clamping, and it has great potential for high-precision microscale manipulation and characterization.