Teaching robots through force sensing

Teaching robots through force sensing

Interviews |
By eeNews Europe

Interestingly, the company was exhibiting at the Merck booth, last October it raised a £9.2 million round of funding led by the venture capital wing of Merck, along with Arie Capital and existing investors. This does not make Merck a majority owner by the way as it only owns between 10 and 15% of Peratech’s shares, noted Stark.

The active-matrix 3D force touch sensor
integrated with a flexible organic LCD.

On display was an active-matrix 3D force touch sensor fully integrated with a flexible organic LCD, creating a multi-point force-touch sensing human machine interface that can conform to the shape of the end application.

The fruit of a collaboration with Merck and FlexEnable, this was a significant technological milestone for Peratech, according to Stark, as no other flexible active-matrix 3D touch sensor with integrated display is available on the market today. The integrated solution was based on FlexEnable’s low-temperature organic thin-film transistor (OTFT) fabrication expertise using Merck lisicon OTFT material technology together with Merck licristal liquid crystal materials. All of the circuitry that drives the organic LCD is integrated alongside the 3D touch sensing elements, making display and force touch a single component in terms of design and system integration. The force sensor provides a raw spatial resolution of 25ppi using 100 by 64 active-matrix sensing elements for the 3D touch sensor. The elements, or sensels, detect both location of touch points and the amount of force applied to each sensel in the contact area, making the theoretical interpolated resolution greater than 10,000 ppi with standard ICs typically used in consumer, automotive, and industrial electronics.

Also demonstrated at the booth was a bare-bone printed 3D touch sensor array displaying the multi-touch force inputs in real-time on a nearby screen, with each touch location displaying the live individual force inputs of anyone’s fingers playing with the interface.

Peratech says its QTC technology can eliminate false touches commonly associated with capacitive touch sensing. One example Stark puts forward is capacitive-based oven interfaces, which he says could be accidentally turned on by young kids. With force sensing built into a control knob, an appliance could detect the grabbing force exerted on the knob and also reject input from small fingers.

Demonstrating the bare-bone printed 3D touch sensor
array, with multi-touch force inputs detected and displayed
in real-time.

Founded in 1996, Peratech has been around for more than 20 years, but it has not been a smooth ride for the company. Despite receiving numerous awards for its QTC materials Peratech entered administration in 2013 after the withdrawal of a major customer led to a cash flow shortfall. The company was then relaunched in March 2014 with the help of a group of investors and Finance Yorkshire Ltd, retaining all its key technical staff through the administration and re-launch, with a new business model. The following year, Peratech had completed a £1million investment round to grow its sales and engineering staff.

So how are things different this time? We asked.

“Their business model did put a lot of risk on the customers. They supplied the QTC materials but then customers had to bear the cost of integration and figure out how to work with the material. I come from the electronics industry and I know this is a difficult business model to support” said Stark talking about the former Peratech.

“We’re not making the customer responsible for figuring out how to use the material, we help with integration. Instead of solely licensing the material, we have process engineers and processes that are already qualified in different industry sectors, so only the final product needs to be qualified. We don’t have to own a factory but the process” Stark explained.

“The first thing we did was to characterize the material for mass production, we’ve had to reformulate the ink to make it a much more mass-production friendly material, easy to print in high yield”.

“Then we worked on its integration, defining design rules and guidelines per application, from a single sensor to a matrix of sensors, so we can offer the characterized materials on mass produced flexible substrates, selling the sensor patches with different algorithms”.

The difficult bit with such thin sensors is how to correctly read out the signal, so the company has worked on a library of filters, including palm rejection filters to build precise sensor models, all this adds value to the devices. Customers are charged a nominal fee for non-recurrent engineering but then, Peratech operates according to a revenue-share model.

So how does it compare to incumbent force sensors, such as those based on piezoelectric materials or carbon-based force sensors? Stark says the QTC offers better integration capabilities.

“There are maybe 2 or 3 types of force sensors we’re running into on a regular basis, but from the feedback we get from customers, the speed of integration and the specifications and characterization of our materials are better and more predictable during testing. We’ve developed testing equipment to be on the factory floor, for spot checks or for every single part to be tested” the CEO commented.

SMK Electronics aims to develop force sensitive
remote controls.

Last summer, Peratech announced its first design-win, integrating its force-sensitive analogue buttons into the Z gaming mouse from Swiftpoint to create ‘Deep Click’ buttons that gives users access to many different button actions based on force input alone. The company also announced a cooperation with SMK Electronics to develop force sensitive remote controls, consumer products and automotive interfaces.

Stark revealed that soon would be starting the mass production of a medical diagnostics sensor for a gait analysis mat, and the company is involved in various projects including industrial robotics and consumer electronics.

“We can create menus with force sensing that work more reliably than capacitive sensors, a less frustrating experience for end-users, the sensors are more rugged, force can be sensed underwater or with gloves on”.

Unsure if Peratech ever broke-even before it entered administration in 2014, the CEO pondered: “Can I tell you when we’ll be profitable? No, but we are in a far better position than we’ve ever been, further down in production with products down the line”.  Back in 2013, a research project had been initiated to use different formulations of the QTC materials for electronic nose applications. It had been observed that the QTC material expand with the absorption of a number of Volatile Organic Compounds (VOCs), altering its electrical characteristics and making those detectable. Is this still on the company’s roadmap? We asked.

“We retained all the IP relating to this, but we are not chasing it for now. In the time I have been at Peratech (since 2014), we’ve received about 20 to 50 requests a week about the physical interactions of our sensors, we’ve learned a lot and we are certainly better prepared to work on it in the future, characterizing the materials’ electrical response”.

“In the future, I could see us giving more to society. In a dreaming mode, we could be in robotics, augmented reality, enabling a better interaction with machines for augmented humanity”. Stark argues that with force sensing applied to hand control, you could immediately see the force patterns of an operator so you could understand what the person is doing. Instead of having to write algorithms, you could teach a robot like you would teach an apprentice, leading by example. The CEO sees prosthetics as another promising market.

“My role at Peratech is to enable all those dreamers to realize their dream product without getting stuck in the minutiae of implementation and coding. We see the most opportunities in tactile sensing but I don’t want to discount the electronic nose application, it may come back, who knows”, the CEO concluded the interview.

Peratech –

Related articles:

Active matrix sensor takes force input on touch-screen

QTC force sensor gains mouse design win

3D force sensing enables true edge-to-edge mobile displays

Peratech ‘print’ smart buttons on any surface

Peratech creates fast-acting electronic nose using its QTC technology

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