Add continuous expressive control to any keyboard with this DIY touch sensor kit. Read more
This project was successfully funded on September 2, 2013.
About this project
What are the TouchKeys?
- The TouchKeys are touch sensors that attach to your keyboard to measure where your fingers contact the keys.
- Use the TouchKeys with any synth to naturally control vibrato, pitch bends, control changes and many other new sounds while playing.
- Put the TouchKeys on your own keyboard with a self-install DIY kit, or go for one of our limited-edition prebuilt instruments.
Transforming the Keyboard
Every keyboard player knows the problem: playing and releasing notes is easy, but shaping what happens in the middle is hard. The acoustic piano wasn't designed to play vibrato, pitch bends or timbre changes, and if you want these techniques on an electronic keyboard, you’re usually stuck with clumsy wheels and pedals or limited aftertouch. The TouchKeys instead put these techniques literally at your fingertips, giving you continuous expressive control with a shake of the wrist or a slide of the finger.
The TouchKeys are capacitive sensor overlays which attach securely to the surface of each key. When you play, the sensors measure the position and contact area of your fingers in real time. This information is sent back to your computer, where the TouchKeys software lets you control any instrument you like. And since they’re attached to your keyboard, you still have the feeling and all the extra controls of your favourite instrument!
The Whole Key a Sensor, with Multi-Touch
The TouchKeys sensors are carefully shaped to fit any keyboard with standard-width keys. The overlays cover the entire playing surface of the key, sensing your finger position in two dimensions (XY). Sensing the touch contact area means the TouchKeys can also distinguish between the fingertip and the pad of the finger. The sensors are even multi-touch: up to three simultaneous touches can be sensed on a single key.
What can I do with the TouchKeys?
The TouchKeys will control any instrument or synth that speaks MIDI or OSC. That includes a huge array of VST and AudioUnit plugins and programs like Max/MSP, Pd, SuperCollider, Kontakt and Reason. (The TouchKeys are not a synth by themselves, but there are tons of great synths out there to use with them, including plenty of free options.)
The TouchKeys software lets you choose from a flexible collection of mappings between touch data and sound. These include:
- vibrato by shaking the hand side-to-side
- pitch bends up and down the key, with an optional feature to snap the bend into the nearest note so you always stay in tune
- MIDI control changes, used for changing volume and timbre, based on absolute or relative finger position or finger contact area
- multi-touch pinch and slide mappings
- triggering extra sounds by tapping with two or more fingers
The software will be open source (GPL), and with the support of the community, we hope to see new mappings develop as time goes on. We will have a forum where users can share ideas, code, patches, and instrument presets.
How does it work?
Each key uses capacitive touch sensing, similar to what's found in smartphone screens, to locate the finger on the key surface. Every key is intelligent, containing its own microcontroller to gather the touch data. Narrow boards you put inside the keyboard collect the data from all the keys and stream it to the computer by USB.
The TouchKeys software combines the USB sensor data with input from your MIDI keyboard, producing an integrated picture of how you play. The software will support Mac, Linux and Windows (updated!). The software works in the background: select the TouchKeys device, point it at your instrument or synth, then forget about it and start playing.
If you've used MIDI instruments before, you may have noticed that control changes and pitch wheel affect all the notes at once. We get around that by sending every note to its own MIDI channel, which means that you can control pitch bend and all MIDI controllers on a note-by-note basis!
What are the reward options?
- Choose from four keyboard sizes ranging from 25 to 88 keys.
- Choose from a DIY kit or a limited-edition pre-built keyboard.
- Choose from the classic keyboard colouring (white/black) or a cool ‘inverted’ look (natural notes are black; sharps are white). We’ll contact you when the project closes to get your choice.
- Or if you just want to support the project, we’ve got a stylish laser-etched pint glass with the TouchKeys logo you can show off to your friends.
Update: The prices below all include UK VAT. If you live outside the EU, we can issue you a refund on VAT following the project, which means a 16% savings on any TouchKeys reward! Full details here.
What do I get in a DIY kit?
Everything you need to transform your keyboard: a TouchKeys sensor for every key which come with a peel-and-stick backings. DIY kits also include controller boards that go inside your keyboard, all the cables you need to attach them together, a mini-USB cable, a complete illustrated installation manual and a copy of the TouchKeys software.
What do I get in a pre-built keyboard?
You get a new-in-box keyboard from Novation or Doepfer with TouchKeys sensors pre-installed, plus a mini-USB cable and a copy of the TouchKeys software. (Support will be through us, as Novation and Doepfer can't provide a warranty on modified keyboards.)
How do I install the TouchKeys?
We are launching this Kickstarter to get DIY TouchKeys kits into your hands. You can install the TouchKeys in an evening with a screwdriver and some DIY spirit-- you need to open your keyboard, but there's no soldering and no programming! The sensors attach to the keys through a high-quality double-sided tape which is very strong but leaves no residue when removed. The tape is pre-attached: just connect the cables, peel and stick. We’ll provide a complete illustrated manual and video examples to guide you through the installation.
We think you’ll want to choose your favourite keyboard for its action and features. But if you prefer a pre-built unit, we’re excited to offer a limited number of TouchKeys sets on new Novation Impulse and Doepfer LMK2+ keyboards. These will be hand-built with the help of the London Music Hackspace and shipped to you.
How do I know if the TouchKeys will fit my keyboard?
The TouchKeys fit almost any keyboard with standard-sized keys. If you want to check whether the sensors will fit your keyboard, download and print the PDF below and try it for yourself: TouchKeys template A4 | TouchKeys template US Letter
The sensors attach to narrow controller boards which you tuck inside your keyboard behind the keys. In practice, every keyboard we’ve seen has space for these, but if in doubt, you might also want to open your keyboard to have a look. Usually there is space either right behind the keys, or on the bottom of the case a couple inches back.
If you want the gory details, here they are! The resolution of the TouchKeys is easily the match of anything on the market today.
- XY position sensing on every key (Y-axis only on the back of white keys, between the black keys)
- White keys: 2432-point resolution in Y axis; 256-point resolution in X axis
- Black keys: 1536-point resolution in Y axis; 256-point resolution in X axis
- Contact area sensing (256-point resolution, with minimum size threshold)
- Up to 3 touches per key (independent Y values; shared X value)
- 200Hz scan rate per key (and little to no perceivable latency)
- USB 2.0 full-speed connection, bus powered (mini-USB connector)
- Any size set from 25 to 97 keys
- 0.8mm thick sensors, plus 0.8mm thick adhesive backing
The feel of the keys is very good: they are slightly more textured than standard piano keys but still smooth, and this gives a nice tactile response when sliding your fingers.
The TouchKeys are the product of over 2 years of research, currently at the Centre for Digital Music at Queen Mary, University of London and previously at Drexel University. I (Andrew McPherson) am the primary developer, and I've had the help of a number of talented researchers and musicians in perfecting the mappings and the playing experience. My previous project, the magnetic resonator piano, has been used in dozens of performances worldwide over the past 4 years, most recently by the London Chamber Orchestra and the band These New Puritans.
Producing the sensors requires an economy of scale. The circuit boards, the chips and the connectors all come down in cost the more we produce. Our project aims to get university research into the hands of musicians, and we are not out for profit: we are pricing these sets to cover materials cost and our time in making and supporting them. We need to raise at least £30k to make the TouchKeys economical to produce at these pledge levels. The limited number of pre-built keyboards reflects what we can build by hand; the extra price covers our time, and there won't be any more added when these are gone!
We're actively working on new mappings and new software features even as this campaign continues, and we want your input. Pledging helps give you a voice in the process.
About the Development
The first idea for the TouchKeys came in late 2010. The choice of capacitive touch technology came from talking with my friend Jeff Snyder about his cool Manta musical controller. By early 2011 I had the first working prototype (here's a video). Since then we've gone through three more revisions; we've improved the shapes, tried different surface coatings, come up with a great way of attaching the sensors to the keys, and most recently added XY sensing to both black and white keys! We've also steadily improved the software. In late 2012 we developed algorithms that make vibrato and pitch bends particularly easy to trigger, control, and keep in tune. You can read more about the TouchKeys development in these papers we have published over the past two years:
A. McPherson, A. Gierakowski and A. Stark. The Space Between the Notes: Adding Expressive Pitch Control to the Piano Keyboard (CHI 2013)
A. McPherson. TouchKeys: Capacitive Multi-Touch Sensing on a Physical Keyboard (NIME 2012)
C. Heinrichs and A. McPherson. A Hybrid Keyboard-Guitar Interface using Capacitive Touch Sensing and Physical Modeling (SMC 2012)
A. McPherson and Y. Kim. Design and Applications of a Multi-Touch Musical Keyboard (SMC 2011)
We’re excited to get these into your hands and to start making music. Thanks for your support!
A big thank you to all the people who have helped make this project a reality! Youngmoo Kim, Adrian Gierakowski, Adam Stark and Christian Heinrichs helped with software/mapping development. Video by Susanna Garcia and Borja Alexandre at Mind the Film. Visual Identity by Matt & Han Ltd. (Hannah Donovan and Matthew Ogle). Keyboard performance by Heen-Wah Wai. Special thanks to Jean-Baptiste Thiebaut, Roland Lamb, Martin Klang and the whole crews at ROLI and Music Hackspace for ideas, and to the Music Entertainment Technology Lab and Centre for Digital Music for supporting the project over the past 2 years. This Kickstarter launch was made possible by the Queen Mary Innovation Fund supported by the EPSRC Impact Acceleration Account.
The TouchKeys are fully made in the UK. The touch sensors are made on a 4-layer printed circuit board process. We have prototypes and quotes for production from two different PCB manufacturing/assembly houses, and we'll check out other companies too before the campaign ends. The companies we use make boards with very tight mechanical tolerances and close attention to the quality of finish.
When this project completes, we'll start right away by ordering the sensors based on our already finished designs. They come to us in 2-octave panels with the electronic components fitted. We'll also order all the cables and rolls of tape for attaching the sensors to the keys. These steps take about 6-8 weeks. From there, we cut the tape to fit each key using our in-house laser cutter, attach the tape to the sensors, and program all the chips. (We expect to do this at Queen Mary, but we also have a quote for external labour if needed.) Those steps will take about 4 weeks. Finally, we give each set a thorough testing, package it up and send it to you as a DIY kit.
Each pre-built instrument will be assembled by hand and carefully tested by a team of 5-10 helpers at Queen Mary and the London Music Hackspace. We've limited the project to only 50 pre-built instruments to make sure we have the capacity to ship them on time.
While we wait for the sensors to be made, we'll be hard at work on the software (currently in alpha state) and device firmware (advanced beta state, at bugfix stage). The basics of gathering the touch data and sending MIDI/OSC are already solid, so we'll be working mostly on new mappings and a nice user interface for editing them. Source code and a user forum will go online before the first units ship in December!
Risks and challenges
I’ve been developing the TouchKeys for 2 years, during which time it has gone through 4 major prototype stages. It is well-tested at this point and nearly complete. I am a composer and have experience designing other instruments for live performance, so I know how important it is that everything works reliably, every time.
I am a full-time Lecturer (Assistant Professor) at Queen Mary, University of London, and there will inevitably be other time commitments during the project. That’s why I have recruited help, including from the London Music Hackspace, for the assembly, testing and distribution of these kits. I’ve also set a realistic deadline for the delivery of these kits so you know what to expect.
The other main risk to the project is production delays owing to component shortages. There are multiple suppliers for most parts, but on the small chance that parts are temporarily unavailable, delivery might be delayed.
Finally, please keep in mind that as a DIY project, I can’t be responsible for how you install the sensors. Opening your keyboard will likely void its warranty, and I can’t replace your keyboard if something goes wrong. On the other hand, I will help however I can in exchanging or repairing TouchKeys parts if anything comes up. I want you to have a great instrument you can use for many years to come.Learn about accountability on Kickstarter
The feeling of the sensor surfaces is highly playable, similar but not identical to the feel of a traditional piano key. There is more texture to the surface (a bit like ivory rather than plastic piano keys), but it isn’t substantially stickier or slipperier than normal. The little “dots” you see on the boards are part of the manufacturing process (vias in the circuit board) and are not felt under the fingers.
In some playing styles, you may occasionally notice that the key edges are more square (especially on the black keys), but this won’t hinder your playing. We recently recorded some ridiculously virtuosic piano playing on these sensors at a Swiss conservatory, so we know they work with normal piano technique!
Some keyboards have aftertouch (key pressure) measurement, usually one measurement for the entire keyboard, though a few keyboards have it on a note-by-note basis. The problems with aftertouch are that it requires the key to be all the way down before it engages, and it requires finger pressure which is physically taxing. The motions on the TouchKeys are very natural and easy to learn, and in our experience are more playable than aftertouch. That said, aftertouch keyboards work beautifully with the TouchKeys-- you can combine the XY and pressure data into a detailed 3D control stream for your synth.
Whatever you want! The TouchKeys are not a synth themselves, so the sound depends on what instruments you connect them to.
Almost certainly yes! The TouchKeys will work with any software instruments that can receive MIDI or OSC messages. That includes nearly everything on that market. And since the TouchKeys software will be open source, support for other non-standard instruments can also be added later by the community.
Yes. As long as your computer has a MIDI output, you can direct the TouchKeys software to send messages there.
Yes. Any touch dimension can generate MIDI polyphonic aftertouch messages, which are supported natively by many synths. The Arturia CS-80V, used in one of the project videos, is one example of a plugin supporting polyphonic aftertouch.
But the TouchKeys work with any synth, whether or not they use polyphonic aftertouch. To achieve independent control of the pitch and timbre of each note, simply configure multiple MIDI channels to produce the same sound (this can be done in nearly every software environment and on many hardware synths). The TouchKeys software will automatically route each note to its own channel.
Mac, Linux and Windows will be supported at ship time.
Any keyboard with standard-size keys should work. The printable PDF above will let you check if the sensors fit your keyboard. We find that keyboards that have wide, flat black keys work the best. This includes every 88-note keyboard we’ve seen, plus semi-weighted instruments like the Novation Impulse and M-Audio Axiom Pro. Some of the smaller synth keyboards (e.g. ESI KeyControl) have black keys that slope downward at the back. These also work, but the sloping key is a challenge. If you have a keyboard like this, we will send you small plastic wedges to provide an even surface on the black keys.
The other consideration is where the controller board that connects the keys will fit. In most keyboards, it fits behind the key bed or at the back of the case, and it doesn’t need much space. However you might want to check for plastic case supports or other boards that would get in the way. If you are unsure, take a picture of your keyboard and send it our way!
So far the list includes: Doepfer LMK2+, Yamaha Clavinova CLP-150, Novation Impulse 49, M-Audio Axiom 61 (1st gen), ESI KeyControl 25, and a Yamaha C5 acoustic grand piano. We will update this space as we are able to verify new models.
Yes, a DIY kit can be used on its own as a controller. We will support a “MIDI emulation” mode where the note triggers at first touch, rather than when the key is pressed. But keep in mind there will be no mechanical key motion without an underlying keyboard, so the playing experience will be different, more akin to some modular synth controllers or iPad than a traditional piano keyboard.
As a university project, we are not out to make a profit, and the reward prices are very much driven by our costs in producing the sensors. Our materials costs include a 4-layer printed circuit board panel, a microcontroller on every key, connectors and cables for each key, adhesive tape, and PCB assembly. There’s also the time to assemble, program and test the kits. Add in VAT, Kickstarter charges and shipping and you get these numbers.
The prebuilt instruments are all individually hand-assembled; this process can’t be easily automated. The price includes the keyboard, the sensor kit and our time to put it together and give it a thorough testing before we send it to you.
No! The DIY kits are peel-and-stick on top of your keyboard. You do have to open the instrument to place the controller boards inside, but this is easy enough on most keyboards. Getting the USB connector out is probably the trickiest part. The most polished result is to drill a small hole in the back of the keyboard for the connector. But if you can’t or don’t want to do this, it’s possible to run the flat ribbon cable out of the case and put the USB adapter board outside the keyboard.
Absolutely not. We have found an excellent high-performance adhesive (3M 4658F) which sticks strongly to the keys but removes cleanly. We have built 3 instruments with this tape; they’ve been taken all over the world and pounded on by groups of schoolchildren, and nothing has fallen off! If anything the adhesive strength increases over time.
Probably yes, but it’s difficult. The adhesive comes off cleanly (no sticky residue), but it is very strong. You can remove the sensors by applying firm upward pressure between key and sensor, starting at the back of the key and working toward the front. Your keyboard will be okay (as long as you don’t use a sharp metal object that could leave scratches), but the sensors are quite thin and might break. For that reason, we don’t officially support TouchKeys removal.
If you know you will want to remove the keys (for example, a temporary installation on a grand piano, or you want to try it on your instrument first), you can use a knife to expose only small patches of adhesive on the back of the keys. The bond will still be reasonably strong, but the removal is much easier and won’t damage the sensors. The instruction manual will illustrate how to do this.
The kits will ship with a professionally-produced manual and video examples. In the meantime, we've put up a quick guide to the installation process using photos we took during prototyping:
We will repair or replace any defective materials on either DIY kits for 60 days or prebuilt instruments for 6 months after you receive it. After that we will maintain a reserve of spare parts and will continue to support you as best we can. We want you to enjoy your keyboard for a long time to come, but please remember that I (Andrew) am a university researcher and not a company, and I cannot promise indefinite free support. Also remember that we can’t provide a warranty for your keyboard when you install a DIY kit.
Not right now. Our goal with this Kickstarter is to get people playing the TouchKeys, and we have set our pricing and funding targets accordingly.
Pledge £1 or more
Keep up-to-date on the TouchKeys Kickstarter, and your name will be mentioned on the website when the project is done. Thanks for your support!Estimated delivery:
Pledge £25 or more
Get a stylish pint glass laser-etched with the TouchKeys logo. Add £25 to any other pledge level to get a pint glass alongside your TouchKeys set.Estimated delivery:Ships anywhere in the world
Pledge £195 or more
4 backers Limited (26 left of 30)
TouchKeys Experimenter's Kit: get 1 octave (12 keys) of TouchKeys DIY sensors to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £330 or more
10 backers All gone!
(Early Bird) TouchKeys 25: get a 2-octave (25 key) TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £360 or more
TouchKeys 25: get a 2-octave (25 key) TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £590 or more
10 backers All gone!
(Early Bird) TouchKeys 49: get a 4-octave (49 key) TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £650 or more
TouchKeys 49: get a 4-octave (49 key) TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £660 or more
3 backers Limited (17 left of 20)
TouchKeys 25 Impulse: Get a limited-edition TouchKeys set pre-installed on a new Novation Impulse 25 keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £770 or more
10 backers All gone!
(Early Bird) TouchKeys 61: get a 5-octave (61 key) TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £850 or more
TouchKeys 61: get a 5-octave (61 key) TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £1,050 or more
0 backers Limited (15 left of 15)
TouchKeys 49 Impulse: Get a limited-edition TouchKeys set pre-installed on a new Novation Impulse 49 keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £1,100 or more
4 backers Limited (1 left of 5)
(Early Bird) TouchKeys 88: get a full 88-key TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £1,200 or more
TouchKeys 88: get a full 88-key TouchKeys DIY sensor kit to install on your keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £1,300 or more
5 backers Limited (5 left of 10)
TouchKeys 61 Impulse: Get a limited-edition TouchKeys set pre-installed on a new Novation Impulse 61 keyboard. Choose from 'classic' or 'inverted' colour scheme.Estimated delivery:Ships anywhere in the world
Pledge £2,500 or more
3 backers Limited (2 left of 5)
TouchKeys 88 Doepfer: Get a limited-edition 88-key TouchKeys set on a new Doepfer LMK2+ keyboard. You'll also be the first to receive your TouchKeys set, and we'll throw in a laser-etched pint glass. Choose from 'classic' or 'inverted' colour scheme. Shipping not included; these keyboards are heavy so we will contact you after with actual shipping charges depending on your location (London pickup possible).Estimated delivery:Ships anywhere in the world
Pledge £3,500 or more
0 backers Limited (3 left of 3)
TouchKeys Elite: Get the TouchKeys 88 Doepfer reward, and also spend a day in London with the team working on new personalised mappings for your instruments. (We'll provide the meals, but travel is not included.)Estimated delivery:
- (35 days)