What is e-Rubber?

e-Rubber is a novel rubber material that can function either as an actuator in response to electrical stimuli, or as a sensor in response to mechanical force. Its basic structure is a thin dielectric elastomer film sandwiched between two electrodes.

As an actuator

As an actuator, the positive and negative charges that accumulate in the opposing electrode when voltage is applied pull the electrodes toward each other, flattening and elongating the sheet.
  • Actuator (motive power source)

    Expands and contracts with electricity on-off Expands and contracts with electricity on-off

    Electricity is transformed into mechanical force

  • Example of use in commercial product

      (moves without sound)
    Large displacement

    Quick movement
      (gentle movement)
    Low energy use
      (does not generate heat)

As a sensor

As a sensor, the change in the amount of electrical charge accumulated in the electrodes is measured when the e-Rubber is pressed or pulled.
  • Sensor

    Senses pressure and converts to electric signals Senses pressure and converts to electric signals

    Transforms mechanical force into electricity

  • Example as pressure sensor

    Can sense minute loads

    Wide sensing range

Principles of e-Rubber

Slide-ring materials

Slide-ring materials are characterized by freely-movable cross-links on chains in polymer networks. In conventional polymeric materials with fixed cross-links, the inhomogeneous distribution of cross-links in the polymer network means that when the material is stretched or pulled tension is concentrated on shorter chains, which then tend to break. With freely movable cross-links, the movement of the cross-links allows the tension to become more homogeneous.
This is achieved with a polyrotaxane architecture, consisting of linear polymers (polyethyleneglycol) with cyclic molecules (cyclodextrin) around them like beads on a string and stopper molecules (adamantane) at each end. The rings form double-loop cross links with rings on other polymer chains, which then act like pulleys on which the polymer strands move to homogenize the structure.
Extra length between the final cross-links and stoppers on the ends of the chains also provide room for extra movement. Slide-ring materials also show excellent restoration properties.

Slide-ring materials

Mechanical force and displacement of actuator

Mechanical force and displacement of actuator
Mechanical force and displacement of actuator glaf Mechanical force and displacement of actuator glaf

Promising fields of use e-Rubber can be used for robots that work on behalf of humans in aging societies, and is promising for use in fields ranging from healthcare to entertainment.

  • e-Rubber
  • Robotics Robotics
  • Soft Robotics Soft Robotics
  • Entertainment Entertainment
  • Medicine / Welfare Medicine / Welfare
  • Automobiles Automobiles

Applications of e-Rubber

AR × e-Rubber haptics

  • Haptics is a field of technology in which the human sensation of touch is simulated and reproduced with vibration and other movement.
  • For humans, touch is an important sense along with hearing and sight in perceiving objects. The amount of information that can be transmitted will increase dramatically with the spread of 5G, and haptics applications that transmit the sense of touch will spread in many fields, including medicine and entertainment.
  • e-Rubber is a soft, lightweight material that can function both as an actuator and as a sensor. In combination with augmented reality glasses, it allows users to experience life-like touch sensations of the softness and other properties of objects depicted with computer graphics.
ar e-rubber ar
  • AR
  • water baloon

Heart surgical training simulator SupeR BEAT

  • This is the first application using e-Rubber. It is an off-pump bypass surgery training simulator.
  • Bypass surgery was conventionally done with the heart stopped, but in recent years surgery with the heart still moving (“off pump”) has become prevalent in Japan. This has led to improved patient outcomes.
  • However, surgery with the heart still beating is very difficult, and surgeons need to practice.
  • This device is currently being sold on the market by EBM, our co-developer.
  • The aim is to standardize surgical techniques together with famous heart surgeons.
  • The new SupeR BEAT was launched in Japan in October of this year.
  • Its characteristics are shown on a separate page.

Arbitrary waveforms with a wide range of
movement patterns are possible

  • Heart rate setting: 60?300 bpm
  • Movement program settings: Up to 100 patterns can be input


  • Tachy/bradyarrhythmia waveforms
  • Random program

Skill training

Individual suture training with reproduction of stressful movements

  • Time can be set
    (fibrillation occurs when time is up)
  • Training with child’s heartbeat
  • Adaptability to unexpected movements with random programming

Non-technical skill training

Team role playing of how to respond when conditions change

  • Response when signal waveforms occur

  • Response manual for each primary doctor
  • Communication between surgeon and assistant

Insole sensor

  • Flexible, lightweight and thin e-Rubber sensors embedded in the soles of shoes can collect data on body balance and shifts in weight.
  • By analyzing each type of data over time, individual gait characteristics can be understood and weakening of the legs with age (frailty) can be detected.
  • A social initiative for preventive medicine that can detect such changes before an individual comes to need nursing care is being carried out in conjunction with Nagoya University and the city of Shinshiro in Aich Prefecture, Japan.
  • In addition to the use of e-Rubber in shoes, attempts are also being made to attach e-Rubber to sports equipment so that it can used in the collection and analysis of various types of data that will help to improve the abilities of athletes.
Insole sensor

Tactile Robot Hands

Toyoda Gosei has developed a “tactile hand” that can sense the shape and hardness of objects using soft and lightweight e-Rubber sensors. This is something robots have not been able to do up to this time.
This tactile hand is being used together with robot systems from QBIT Robotics to enable robots to perform more human-like work.
Our aim is for the spread of practical robots that will be beneficial in future aging societies.


Barista robot

This robot combines Toyoda Gosei’s tactile hand, made with light, flexible and sensitive e-Rubber sensors, and a robot system created by QBIT Robotics Corp.

Salad robot

With e-Rubber sensors on their fingers, these robot hands possess a “sense of touch” and can perform work in a more human-like way with the ability to sense the shape and softness of objects, an ability that conventional robots have lacked. Highly accurate e-Rubber sensors enable just one hand to handle various objects, whether they are heavy, light (less than 100 grams), or soft.
Aging societies with fewer children are rapidly expanding in many advanced countries, and one of the serious social issues is a labor shortage in manufacturing, service, social-welfare and many other fields. Robots that perform work on behalf of humans hold much promise. Toyoda Gosei is collaborating with QBIT Robotics, a startup that develops systems centered on collaborative robots that work together with humans for use in the service industry, including food service and entertainment. The two companies aim to develop practical robots that can be used for support in aging societies with fewer children.

Salad robot