2 Tactile Sensor Manufacturers in 2022

What Is a Tactile Sensor?

A tactile sensor is a sensor that mimics the human sense of touch.

The technology is based on a sensor that converts pressure and vibration of a contact surface into an electrical signal.

In addition, tactile sensor can be integrated with multiple pieces of information, such as temperature sensitivity, to estimate the texture of sensitive objects.

Tactile sensor is essential for the development of robotics technology, not only for evaluating the properties and texture of objects, but also because they play an important role in basic human movements, such as grasping objects with appropriate force and writing with a pen in one's hand.

Uses of Tactile Sensors

Tactile sensors are found to be applied in medical care, robotics, and industrial enviorments.

1. Medical 

Since tactile sensors can evaluate the hardness of an object, they can detect the presence of "lumps" originating from breast or prostate cancer with high sensitivity, contributing to the early detection of cancer.

Also, by evaluating roughness caused by surface roughness, it can be used for quantitative evaluation of dermatitis and xeroderma.

2. Robotics

In robotics, the development of a sensor that mimics a finger provides information for adjusting grip strength as a sensor for robotic hands.

3. Industrial

In industrial uses, tactile sensors can be useful for quality control by monitoring the texture of products.

4. Haptics for VR

In the world of VR (Virtual Reality), goggles for 3D have already been commercialized. The application of suits and gloves to this VR and tactile sensors are being worked on.

Principle of Tactile Sensors

Tactile sensors utilize various physical phenomena to convert contact forces on objects into electrical quantities, and are composed mainly of conversion devices (sensors: elements). These electrical signals are analyzed via signal and information processing circuits. In principle, the sensor can employ a variety of detection modalities.

For example, one method is to detect the electrostatic capacitance resulting from changes caused by the application of pressure in a space sandwiched by conductive Depending on the application, piezoelectric ceramic elements (PZT: lead zirconate titanate) are generally used as the sensor element in many cases. Piezoelectric ceramic elements, also called piezoelectric elements, produce voltage changes when pressure is applied. This is called the piezoelectric effect.

The arrangement of ions in the solid crystal of a piezoelectric element changes when pressure is applied, causing a phenomenon called electric polarization, in which one end of the crystal is charged with positive electricity and the other with negative electricity. Pressure information and vibration frequency information are converted into electrical signals by the piezoelectric element, which can then be converted into tactile information via analog and digital processing circuits composed of ASICs and other devices.

In addition, as an optical principle, the contact position of an object on the sensor surface can be captured by detecting changes in the scattered light in the optical waveguide inside the sensor.

Other Information on Tactile Sensors

1. Tactile Sensor Market

The tactile sensor market size is projected to reach $16,083.8 million by 2025 from $8,204.9 million in 2019.

Haptic sensors are one of the key elements supporting the development of robots that can work together with humans. For example, RoCycle, a robot being developed at MIT in the U.S., has tactile sensors built into its hands to identify materials so that it can recognize and sort paper, plastic, and metal.

At the Pohang University of Technology in Korea, a human fingerprint sensor is being developed using nanosprings that can sense minute pressure and vibration. The results of the development include a machine learning analysis of the information obtained from the tactile sensor and the successful differentiation of eight types of fibers with an accuracy of 99.8%. As the accuracy of tactile sensors improves, demand for tactile sensors is expected to increase, especially in the robotics industry.

2. MEMS Tactile Sensors

MEMS (Micro Electro Mechanical Systems) is a device in which sensors, electronic circuits, etc. are integrated on a substrate using microfabrication technology.

In recent years, ultra-sensitive tactile sensors using MEMS technology have been attracting attention.

3. Expansion into the Field of Haptics

Not only in the world of VR, Haptics is also finding its way into various familiar fields. Examples include home buttons on smartphone screens, navigation systems on the instrument panels of electric vehicles, styluses for electronic authentication, and PC keyboards.

In these fields, how small, lightweight, thin, and realistic tactile sensors can be realized is critical in terms of tactile technology. Therefore, manufacturers are working hard to develop cutting-edge MEMS technology, piezoelectric device technology, and application software.