Designworks - Liar Liar Pants On Fire!

Hotpants Header

Designworks is a leading creative design consultancy, with clients such as BP, Clarks, British Airways and Dell. They approached Sensum to help devise a system that could tell if someone has told a “little white lie”.




5th October 2017

Body and Contextual Data

Heart Rate and GSR


  • Designworks


With a short project period, how do we produce a portable ‘lie detector’ that will detect when a person might be lying from their biometrics and activate heat pads in a pair of pants? With Wi-Fi being used to communicate to the heat pads, how do we perform offline processing of data and in real time? The app would be used for promoting the NOW TV Show Sick Note, starring Rupert Grint, Nick Frost and Don Johnson.

’pants’ as in underwear, not the North American ‘pants’!

Close Up Of Pants


To understand what happens when someone is under the stress of lying, we divided our time between 2 weeks of research and validation and 2 weeks of development. Using our Sensumites as test subjects in a range of scenarios, we were able to build an understanding of what happens to a person’s physiology when they tell a lie. For instance, we ran some tests during our morning stand-up meetings where certain individuals were told to slip in a lie when it was their turn to speak. Each participant wore a Mio Link heart rate band and a Shimmer 2r GSR sensor and no one, except the coordinator and the participant, knew who would be lying that day, to avoid bias.

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Through our research, we identified an increase in biometric activity correlated to the period before someone told a lie. It was key for the system to run offline (unlike in our other applications where data is streamed in realtime to our EmotionAI Web API - where the heavy lifting and data processing is done) so we needed to design our data emotions recognition algorithms to work fast on a relatively low powered mobile phone. We solved this by prototyping the emotion recognition system using our API and ported key real-time analysis functionality to a modified version of our SDK running on an Android mobile phone.

It is worth noting that our model was not a perfect lie-detector. It actually detected stress level responses that were not always related to lying, just as a traditional lie detector (polygraph) does, but it was still effective. We must note that the notion of lie detection is a misnomer, often described as pseudoscience at best. To get as close to the notation of detecting “lies” as possible with the biometrics we were collating and the environment in which they were being measured we based the system on the knowledge we gained from in house lie-testing and the best current research, aided by our in house experts and partnerships with world leading emotions researchers.


Working with Designworks, NOW TV launched a national campaign to promote Sick Note with a comedy video that demonstrated its capabilities. This was followed with tests on members of the public, challenging them to see how good they are at lying.

‘Sensum’s understanding of emotions helped us to create a unique campaign for our client, in which we could explore new ground in biometrically driven experiences’. - Sean Miles Director of Prototyping at Designworks Windsor Ltd.

Pants And Gf

Adam Booth

Platform Manager