TPU (Thermoplastic Polyurethane) has outstanding properties such as flexibility, elasticity, and wear resistance, making it widely used in key components of humanoid robots like exterior covers, robotic hands, and tactile sensors. Below are detailed English materials sorted out from authoritative academic papers and technical reports: 1. **Design and Development of an Anthropomorphic Robotic Hand Using TPU Material** > **Abstract**：The paper presented here approaches to solve the complexity of an anthropomorphic robotic hand. Robotics is now the most advancing field and there has always been an intention of mimicking human – like actuation and behavior. An anthropomorphic hand is one of the approaches to imitate human – like operations. In this paper, the idea of developing an anthropomorphic hand with 15 degrees of freedom and 5 actuators has been elaborated as well as the mechanical design, control system, composition, and peculiarities of the robotic hand have been discussed. The hand has an anthropomorphic appearance and also can perform human – like functionalities, for example, gripping and hand gestures representation. The results reveal that the hand is designed as one part and does not need any kind of assembly and it exhibits an excellent weight lifting capacity, since it is made of flexible thermoplastic polyurethane (TPU) material, and its elasticity also ensures that the hand is safe for interacting with humans as well. This hand may be used in a humanoid robot as well as a prosthetic hand. The limited number of actuators makes the control simpler and the hand lighter. 2. **Modification of a Thermoplastic Polyurethane Surface for Creating a Soft Robotic Gripper Using a Four-Dimensional Printing Method** > One of the avenues for the development of functional gradient additive manufacturing is the creation of four – dimensional (4D) printed structures for soft robotic gripping, achieved by combining fused deposition modeling 3D printing with soft hydrogel actuators. This work proposes a conceptual approach to creating an energy – independent soft robotic gripper, consisting of a modified 3D printed holder substrate made from thermoplastic polyurethane (TPU) and an actuator based on a gelatin hydrogel, allowing programmed hygroscopic deformation without using complex mechanical constructions. > > The use of a 20% gelatin – based hydrogel imparts soft robotic biomimetic functionality to the structure and is responsible for the intelligent stimulus – responsive mechanical functionality of the printed object by responding to swelling processes in liquid environments. The targeted surface functionalization of thermoplastic polyurethane in an argon – oxygen environment for 90 s, at a power of 100 w and a pressure of 26.7 pa, facilitates changes in its microrelief, thus improving the adhesion and stability of the swollen gelatin on its surface. > > The realized concept of creating 4D printed biocompatible comb structures for macroscopic underwater soft robotic gripping can provide noninvasive local gripping, transport small objects, and release bioactive substances upon swelling in water. The resulting product can therefore be used as a self – powered biomimetic actuator, an encapsulation system, or soft robotics. 3. **Characterization of Exterior Parts for 3D-Printed Humanoid Robot Arm with Various Patterns and Thicknesses** > With the development of humanoid robotics, softer exteriors are needed for better human – robot interaction. Auxetic structures in meta – materials are a promising way to create soft exteriors. These structures have unique mechanical properties. 3D printing, especially fused filament fabrication (FFF), is widely used to create such structures. Thermoplastic polyurethane (TPU) is commonly used in FFF due to its good elasticity. This study aims to develop a soft exterior cover for the humanoid robot Alice III using FFF 3D printing with a Shore 95A TPU filament. > > The study used a white TPU filament with a 3D printer to manufacture 3DP humanoid robot arms. The robot arm was divided into forearm and upper arm parts. Different patterns (solid and re – entrant) and thicknesses (1, 2, and 4 mm) were applied to the samples. After printing, bending, tensile, and compressive tests were conducted to analyze the mechanical properties. The results confirmed that the re – entrant structure was easily bendable towards the bending curve and required less stress. In compressive tests, the re – entrant structure was able to withstand the load compared to the solid structure. > > After analyzing all three thicknesses, it was confirmed that the re – entrant structure with a 2 mm thickness had excellent characteristics in terms of bending, tensile, and compressive properties. Therefore, the re – entrant pattern with a 2 mm thickness is more suitable for manufacturing a 3D – printed humanoid robot arm. 4. **These 3D-Printed TPU “Soft Skin” Pads Give Robots a Low-Cost, Highly-Sensitive Sense of Touch** > Researchers from the University of Illinois Urbana – Champaign have come up with a low – cost way to give robots a human – like sense of touch: 3D – printed soft skin pads that double as mechanical pressure sensors. > > Tactile robotic sensors usually contain very complicated arrays of electronics and are quite expensive, but we have shown that functional, durable alternatives can be made very cheaply. Moreover, since it’s just a question of reprogramming a 3D printer, the same technique can be easily customized to different robotic systems. Robotic hardware can involve large forces and torques, so it needs to be made quite safe if it’s going to either directly interact with humans or be used in human environments. It’s expected that soft skin will play an important role in this regard since it can be used for both mechanical safety compliance and tactile sensing. > > The team’s sensor is made using pads printed from thermoplastic urethane (TPU) on an off – the – shelf Raise3D E2 3D printer. The soft outer layer covers a hollow infill section, and as the outer layer is compressed the air pressure inside alters accordingly — allowing a Honeywell ABP DANT 005 pressure sensor connected to a Teensy 4.0 microcontroller to detect vibration, touch, and increasing pressure. Imagine you want to use soft – skinned robots to assist in a hospital setting. They would need to be regularly sanitized, or the skin would need to be regularly replaced. Either way, there’s a huge cost. However, 3D printing is a very scalable process, so interchangeable parts can be inexpensively made and easily snapped on and off the robot body. 5. **Additive Manufacturing of TPU Pneu – Nets as Soft Robotic Actuators** > In this paper, the additive manufacture (AM) of thermoplastic polyurethane (TPU) is investigated in the context of its application as soft robotic components. Compared to other elastic AM materials, TPU reveals superior mechanical properties with regard to strength and strain. By selective laser sintering, pneumatic bending actuators (pneu – nets) are 3D printed as a soft robotic case study and experimentally evaluated with respect to deflection over internal pressure. Leakage due to air tightness is observed as a function of the minimum wall thickness of the actuators. > > To describe the behavior of soft robotics, hyperelastic material descriptions need to be incorporated in geometric deformation models which may be — for instance — analytical or numerical. This paper studies different models to describe the bending behavior of a soft robotic actuator. Mechanical material tests are applied to parameterize a hyperelastic material model to describe additively manufactured thermoplastic polyurethane. > > A numerical simulation based on the finite element method is parameterized to describe the actuator’s deformation and compared to a recently published analytical model for such an actuator. Both model predictions are compared with the experimental results of the soft robotic actuator. While larger deviations are achieved by the analytical model, the numerical simulation predicts the bending angle with average deviations of 9°, although the numerical simulations take significantly longer for the calculation. In an automated production environment, soft robotics can complement the transformation of rigid production systems towards agile and smart manufacturing.
Post time: Nov-25-2025