Tunable Haptic Chair

The present application claims the filing benefits of U.S. provisional application Ser. No. 63/638,651, filed Apr. 25, 2024, which is hereby incorporated herein by reference in its entirety.

The present invention relates generally to a chair for cinema, Performing Art Centers (PAC), education, live entertainment or recording studios.

It is known to provide chairs that use haptic devices to create an immersive experience by distributing the haptic output to known locations in the chair. Typically, such vibrations are caused by multiple vibrating units attached at different parts of the chairs.

The present invention provides a haptic system that includes a haptic device that mechanically interfaces with a chair or other structure. The haptic device operates to generate a vibration output (based on a programmed function or vibration profile or pattern) that imparts vibration or movement of the structure in a desired profile or pattern and at desired frequencies and amplitudes. The haptic device is a single unit mounted at the chair back or seat of the chair and is operable to impart vibration at the back or seat of the chair, which, due to the mechanical interface and the structure of the chair, vibrates different parts of both the back and the seat of the chair. The haptic system thus provides a tunable chair that vibrates at different patterns and profiles based on the input provided to the haptic device.

For example, a chair includes a seat portion and a back portion and a haptic device attached at one of the seat portion and the back portion. Responsive to receiving an electronic input, the haptic device vibrates to impart vibration at one or more of the seat portion and the back portion. Responsive to the haptic device vibrating at a first frequency, a first region of the chair vibrates at a greater amplitude than a second region of the chair that is spaced from the first region. Responsive to the haptic device vibrating at a second frequency different than the first frequency, the second region of the chair vibrates at a greater amplitude than the first region of the chair.

These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.

Referring now to the drawings and the illustrative embodiments depicted therein, an individual chairmay be a standalone consumer/residential chair, or may be part of a stadium or theater or auditorium seating configuration, which comprises a plurality of chairs arranged in rows (although only one chair is shown in), or may be an vehicular chair or seat configured for mounting within a vehicle, such as an automotive vehicle, airplane or other vehicle. In some examples, the chairmay be part of a virtual reality system, such as a driving simulator or flight simulator. The individual chairs of the seating configuration may be arranged one next to another, optionally with an arm restat a stanchionat each side of the chair, or the chairs may be mounted along a rail or beam that mounts to spaced apart support structures. Each arm restbetween adjacent chairs of the row of chairs may be shared by the adjacent chairs. The chairincludes a seat or seat portionand a backboth attached at respective stanchions, with the arm restand stanchionat each side of the seat portion. The chairincludes an actuator or haptic devicethat functions to vibrate an attaching plate that attaches the actuator at the backof the chair. The actuatoroperates to vibrate at different magnitudes and frequencies responsive to an input (that may correspond with video images being displayed or audio signals being broadcast at the seating area), whereby the vibrations are felt by a person sitting in the chair at different locations of the chair, including at different locations of the seat portionand the back portion.

The actuator and chair cooperate to provide a “tunable chair” that converts the incoming electrical signal (provided to the actuator) to mechanical energy (haptic) and transfers this mechanical energy to different regions of the mechanism based on the mechanical interface design. The mechanical interface energy transfer can vary by amplitude, position, time, and phase. The benefit of this system is that it provides an enhanced experience with only a single haptic device, which has the ability to excite different regions of the mechanism or structure to give the desired effect to the user.

As shown in, the actuator or haptic devicereceives an input from a frequency controller modifier, with the input being based on music or audio or video that is to be experienced while the user is sitting in the chair. For example, a function generatormay generate a function or output (in a range of 1 Hz to 40 kHz) that is based on the corresponding music or audio or video, and that is provided to the frequency controller modifier. The frequency controller modifiercontrols the haptic device in accordance with the received input, which causes the haptic deviceto vibrate at the desired or set or programmed frequencies and amplitudes. The haptic device, which (in the illustrated embodiment) is attached at the chair back, vibrates and, via the mechanical interface to the seat structure and/or mechanism, causes different portions of the chair (back and seat portion) to vibrate the desired amount and at the desired locations. The mechanical response (M) is variable in both amplitude and position based on the input (M) from the haptic device, thereby providing a tunable device or chair.

The haptic device may comprise a suitable vibrating device that is operable to vibrate an actuating plate or attaching plate at a desired amplitude and/or frequency. Examples of suitable devices include the Powersoft, Clark or Buttkicker Mover. Thus, a programmed input is provided, and the single haptic device responds to the input by vibrating at the desired pattern or profile, whereby, due to the mechanical interface between the haptic device and the seat, the seat vibrates at the desired pattern or profile.

In the illustrated embodiment, the actuator or haptic device is disposed at the chair back. However, the actuator may be disposed at the seat portion, depending on the particular application. Also, the chair is shown as an auditorium or theater chair that has the seat portion pivot up when not in use. However, aspects of the actuator and haptic system may be implemented on various seating applications, such as cinema, performing art centers, live entertainment, auditoriums, educational seating, etc. Also, aspects of the actuator and haptic system may be implemented in non-seating applications, where the actuator operates to provide a desired and tunable haptic response at a selected device or structure.

The physical transmission of low audio frequencies through the use of the device resolves standing wave and frequency response issues universally plaguing audio playback environments. The system is suitable for use in various applications, such as for use in critical listening environments, and for transmitting low and subsonic audio frequencies through direct bodily contact. With an additional room-decoupling apparatus and headphones, the system can be used to create a discrete, extra-range listener audio response curve of 1 Hz to 20 kHz. The system can be used as a stand-alone subwoofer system for gaming media and playback, or as a spiritual and meditative tool by transmitting chosen resonant frequencies, or as a communication device for hearing impaired through chair-delivered tactile signaling.

The chair (or other structure) has a single actuator that, when actuated, imparts vibrations in the desired pattern or profile at different locations of the chair or structure, including at both the back portion and the seat portion. The chair is configured to respond to vibration from the single unit or actuator or haptic device (e.g., at back of chair) so that the user sitting in the chair feels different vibrations at different parts of chair, based on the input provided to the haptic device and the mechanical interface of the device with the chair.

Referring to, when the actuatoroperates to impart vibration at one or more portions or regions of the chair, the actuatorvibrates at determined frequencies and amplitudes. Different frequencies and amplitudes of the actuatorimpart vibration of different regions of the chairat different amplitudes due to the different natural frequencies of the regions of the chair. In other words, responsive to the actuatoroperating at one frequency, a first portion or region of the chairmay vibrate at a greater amplitude than a second portion or region of the chairand, responsive to the actuator operating at a different frequency, the second portion or region of the chairmay vibrate at a greater amplitude than the first portion or region of the chair. Accordingly, although the source of the vibration (i.e., the actuator) is at the same position of the chairand does not move and is operable to interface with and directly vibrate a region of the chair, the different regions of the chairvibrate at different amplitudes when the actuatoris operated at different frequencies so that the user sitting at the chairperceives greater vibration at different regions of the chairwhen the actuatoris operated at different frequencies. Moreover, vibration at the different regions of the chairmay exhibit a phase shift relative to vibration imparted by the actuatorand relative to one another and will give the perception of movement of the vibration to the user from one region to another.

In the illustrated example of, the actuatoris disposed at a central region of the back portionof the chairand the back portionmay include four quadrants or regions-. Similarly, the seat portionmay include four quadrants or regions-. In other examples, the seat portionand the back portionmay have any suitable number of differently configured regions. Each region-of the back portionand each region-of the seat portionmay have its own respective natural frequency, or more than one region-of the back portionand/or more than one region-of the seat portionmay have the same or similar natural frequency to one another. Thus, as the actuatoris operated at different frequencies, the regions-of the seat portionand the regions-of the back portionvibrate at different amplitudes relative to one another.

shows accelerometer sensor data captured during operation of the actuatorat an example chair, with the actuatoroperating to produce a pink noise signal, and with the accelerometer sensor data representative of vibration at the first region, the second regionand the third regionof the back portionof the chair. As shown, the regions of the back portionreact differently to frequencies generated by the actuator, demonstrating varied displacements and phase shifts from one another at the same frequency. For example, at a frequency of about 37 Hz, the first regiondemonstrates a displacement of about 0.024 millimeters and a phase shift of about 150 degrees, the second regiondemonstrates a displacement of about 0.018 millimeters and a phase shift of about 150 degrees, and the third regiondemonstrates a displacement of about 0.004 millimeters and a phase shift of about-50 degrees. This may result in a more intense vibration felt by the user at the upper regions of the back portionthan at the lower regions of the back portion, and maybe a perceptible difference between the left side of the upper region compared to the right side of the upper region. The sum of outputs at the regions of the chairmay be equal aF1+pF1, where F1 is the input from the actuator, a is the amplitude percentage change from F1 (less than, equal to, or greater than), and p is the phase change from F1 (+180 degrees).

Accordingly, the function generatormay control the haptic actuatorto operate at different frequencies based on the natural frequencies or vibration reactions of the seat portionand the back portion, resulting in the desired vibration pattern or profile to be experienced by the user. The control function from the function generatormay be based on media (e.g., visible media like a movie and/or audible media like music or sound effects) displayed to the user simultaneous with operation of the actuator. Operation of the actuatormay utilize characteristics of the methods and systems described in U.S. provisional patent application Ser. No. 63/779,403, filed Mar. 28, 2025, which is hereby incorporated herein by reference in its entirety.

In some examples, the control function for the actuatormay be based on natural frequencies or characteristics of the chairlearned via modal analysis. For example, during operation of the actuatorat different frequencies, accelerometer sensor data may be captured that is representative of the different regions of the chair. This sensor data may be used to determine reaction profiles for the regions that indicate frequencies at which the regions are reactive (and thus impart vibration felt by the user) and frequencies at which the regions are not reactive or less reactive (and thus do not impart vibration easily felt by the user). This may allow a chair to be retrofit with the actuator. In such an example, the actuator may be controlled to provide a pattern of vibrations that are selected or tuned for the particular reaction profiles of the chair regions.

Optionally, each region-of the seat portionand each region-of the back portionmay include a feature or characteristic that causes the region to have a specific natural frequency and thus vibrate at different amplitudes responsive to different operating frequencies of the actuator. For example, the portions of the chaircorresponding to the regions may be formed from different materials, have different structure disposed at the regions, have different shapes or contours, and the like. In other words, the natural frequency of each region of the chairmay be based at least in part on the material of the chair at that region, the structure of the chair at that region, the shape or contour of the chair at that region, and the like. For example, the seat and back frame or support structure may be designed to vary in material and/or shape and/or thickness so that multiple regions of the seat and back have different respective natural frequencies or reaction profiles. The seat and back may have any number of portions or regions with designed or selected reaction profiles or may have continuous changes in structure or material across the seat and back to provide a continuously varying reaction profile at the chair. Each portion or region may have its own respective natural frequency so that each portion or region reacts differently to a vibration input from the actuator. The natural frequency differences between the different portions or regions are sufficient enough so that a person sitting in the chair can perceive heightened vibrations in different portions or regions. For example, the natural frequency may vary by around 10 Hz or less or around 20 Hz or 40 Hz or more between other portions or regions, such as adjacent portions or regions.

As shown in, vibration of the seat portionmay peak in amplitude at a frequency of about 28 Hz and vibration of the back portionmay peak in amplitude at a frequency of about 31 Hz. Thus, the user may perceive vibration at different portions or regions of the chairresponsive to changes in frequency from the actuator of only a few hertz, such as differences of five hertz or less, three hertz or less, one hertz or less, and the like.

Moreover, the control signal for the actuatormay include a pure or single tone or a complex tone. For example, a complex tone such as pink noise may apply frequencies to the chair(e.g., 51 Hz in) that do not create a resonance at any one portion or region of the chair, such that the vibration may be distributed throughout and perceived by the user at multiple locations or throughout the chair. Single tones (e.g., 49 Hz in) may result in similar vibration amplitudes at multiple portions or regions of the chair.

Thus, for example, a complex tone input may be provided based on the varying natural frequencies or varying response profiles designed into (or determined from) the structure of the chair. At any point in time, the complex tone input may cause greater excitation at a plurality of locations or regions of the seat portionand back portionof the chairwith reduced excitation at other locations or regions. As the tone input changes, different regions of the seat portionand back portionof the chairreact differently to provide the desired vibration profile experienced by the person sitting in the chair. The chairmay have any number of regions that are specifically targeted or excited (or not excited) by the input, depending on the particular chair design and characteristics and desired user experience. For example, the seat portionof the chairmay have four or more targeted regions (with each region having a respective known natural frequency or reaction profile) and the back portionof the chairmay have four or more targeted regions (with each region having a respective known natural frequency or reaction profile), such as eight or more targeted regions at each of the seat portionand the back portionof the chair(e.g., four corner regions of the seat portion and four corner regions of the back portion, and optionally one or more central regions of the seat portion and the back portion, with each corner region and each central region having a different reaction profile so that a desired vibration profile of the overall chair can be achieved via a single actuator). If several of the regions or all of the regions are to be excited at the same time, the input may include all of the respective natural frequencies (or close to the natural frequencies) to provide the increased vibration across all of the regions and thus across the entire chair.

Different materials may have different mass or densities or different stiffness, resulting in different natural frequencies and thus different vibration reactions to an imparted frequency from the actuator. For example, the chairmay comprise one or more plastic or rubber or metallic materials, or a particular material (e.g., engineered plastics or other suitable material) may be injection molded or otherwise formed with varying densities, such as established via different pressures at different areas of the mold, different fillers at various regions, different cooling rates of the molded component, etc. The seat portionand the back portionmay comprise the same material, or different materials from one another based on the desired natural frequency. In one example, the chairmay comprise a first or primary material (e.g., a plastic material) with a body or element formed from a second material (e.g., another plastic material or a rubber material or a metallic material) disposed at one or more regions of the chair. The second material may have a different natural frequency from the primary material so that, when the actuatoris operated to impart vibration at a frequency that corresponds to the natural frequency of the second material, the user may perceive vibration at regions corresponding to the body or element and not at other portions of the chair(or may experience reduced vibration at the other portions or regions of the chair). The element may be attached at or at least partially embedded in the first material at the region of the chair. For example, the element may include a metallic plate attached to a portion of the chairor the element may include a rubber or plastic component at least partially embedded in the chair(e.g., during an injection molding process of forming the chair). Optionally, the element may include a pin, a tuning fork, a screw or bolt, and the like.

Further, the chairmay have one or more structures that correspond to different regions of the chair. For example, the chairmay have one or more recesses or cavities or hollow portions that correspond to respective regions or may have varying recesses or cavities or hollow portions across the seat and/or back. This may cause the chairto have different natural frequencies at regions corresponding to the recesses or cavities or hollow portions and thus different vibrations may be felt by the user at regions corresponding to those portions responsive to the actuatoroperating at a given frequency. The recesses or cavities or hollow portions may contain another material, (e.g., a fluid, a gas, a solid, a powder and the like) that causes the region to vibrate responsive to a desired frequency.

The chair(e.g., the seat or back support structure or frame) may have different thicknesses or widths or depths. For example, the seat portionmay be gradually thinner or gradually thicker from the back portionto an outer end of the seat portiondistal from the back portion. This may allow the actuatorto “move” the vibration felt by the user along the seat portionby gradually adjusting the frequency at which the actuatoris operating. Similarly, the back portionmay be gradually thinner or gradually thicker from the seat portion to an upper end of the back portiondistal from the seat portion. Moreover, portions of the chairmay include bumps or ridges or protrusions or curves or edges or other suitable contours to cause the corresponding region to vibrate responsive to a desired frequency of the actuator.

Optionally, sides of the chairmay be symmetrical to one another, and thus have corresponding regions that vibrate responsive to a given frequency of the actuator. That is, a left side of the chairmay react similarly or the same as a right side of the chairwhen the actuatoris operated. In some examples the chairmay be asymmetrical so that the two sides of the chairreact differently to operation of the actuator. That is, when the actuatoris operated at one frequency, a first region at one side of the chairmay vibrate at a greater amplitude than a corresponding second region at the other side of the chairand when the actuatoris operated at another frequency, the second region may vibrate at a greater amplitude than the corresponding first region. By varying the seat and/or back structure or material to have asymmetrical reaction profiles, the actuator may function to “move” the vibration felt by the user across the seat and/or back (or move the vibration forward or rearward) so that the user perceives vibration moving from one side of the seat and/or back to the other side of the seat and/or back.

Optionally, the actuatormay be disposed at an insert or haptic plate that may be configured for attachment at an existing chair, such as at a back portion or seat portion of an existing chair. The insert may include vibration elements, such as fingers or tuning forks or extension portions, that extend from the actuator to different portions or regions of the chair. Responsive to operation of the actuator, one or more of the fingers may vibrate at different amplitudes to impart vibration at the corresponding regions of the chair. For example, each finger may vibrate at a perceptible amplitude (i.e., an amplitude that causes a user sitting at the chair to feel the vibration) responsive to a corresponding frequency of the actuator.

Thus, the chair is designed or formed or modified to have varying reaction profiles at multiple regions of the seat and/or back of the chair, such that, when a haptic device or actuator is actuated to impart vibration at a region of the chair (e.g., a mounting region where the actuator is mounted at the seat or back), the multiple regions of the seat and/or back react differently to the imparted vibration. By varying the material or structure or profile of the seat and/or back so that the different regions have different respective natural frequencies, the vibration reaction profile varies across the different regions and allows the actuator and system to move or adjust the vibration at the different regions via a single vibrating actuator mounted at the seat or back of the chair. Although shown and described herein as having a single actuator or haptic device disposed at or mounted at the back of the chair, the actuator or haptic device may be disposed at or mounted at the seat of the chair, such as at an underside of the seat or within the seat frame. Optionally, an actuator or haptic device may be disposed at or mounted at the back of the chair and another actuator or haptic device may be disposed at or mounted at the seat of the chair, with each actuator imparting a respective vibration at the respective mounting region. Optionally, the chair may be a consumer/residential chair for a home theater or a vehicular chair within a vehicle, whereby the tuned vibration profile of the chair may allow the home theater or automotive sound system to reduce the need or output of a subwoofer to achieve a similar effect or user experience. Further, the chairmay be part of a virtual reality system, such as a driving simulator or flight simulator, where vibration at the chairmay be representative of and/or correspond to an audio experience of the user, a visual experience of the user, and/or a physical experience of the user (e.g., vibration of the simulated vehicle such as due to bumps in the virtual road or vibration of the simulated airplane such as due to simulated turbulence).

In one aspect, a chair includes a seat portion and a back portion. A haptic device is attached at one of the seat portion and the back portion. Responsive to receiving an electronic input, the haptic device vibrates to impart vibration at one or both of the seat portion and the back portion. Responsive to the haptic device vibrating at a first frequency, a first region of the chair vibrates at a greater amplitude than a second region of the chair that is spaced from the first region. Responsive to the haptic device vibrating at a second frequency different than the first frequency, the second region of the chair vibrates at a greater amplitude than the first region of the chair. This aspect may include one or more of the following optional features.

In some examples, the haptic device is disposed at the back portion and vibrates to impart vibration at the back portion. In some implementations, the haptic device is disposed at the seat portion and vibrates to impart vibration at the seat portion. In some aspects, the electronic input corresponds to audio or video signals being experienced by a user of the chair simultaneous with the vibration.

In some examples, with the haptic device vibrating at the first frequency, vibration at the first region of the chair is perceivable by a user of the chair and vibration at the second region of the chair is imperceivable by the user of the chair. In further examples, with the haptic device vibrating at the second frequency, vibration at the second region of the chair is perceivable by a user of the chair and vibration at the first region of the chair is imperceivable by the user of the chair.

The haptic device vibrates to impart vibration at the seat portion and at the back portion. For example, the haptic device vibrates at frequencies between 1 Hertz and 40 Kilohertz. Optionally, the haptic device may vibrate at frequencies of 1 Hertz and lower and/or at frequencies of 40 Kilohertz and higher.

In some implementations, the first region is at the seat portion. Further, the second region may be at the seat portion and spaced from the first region. For example, the first region may be at a left side portion of the seat portion and the second region may be at a right side portion of the seat portion. Further, responsive to the haptic device vibrating at a third frequency, a third region of the chair may vibrate at a greater amplitude than the first region of the chair and the second region of the chair, where the third region is at a central portion of the seat portion between the right side portion and the left side portion. Optionally, the first region may be at a front end portion of the seat portion and the second region may be at a rear end portion of the seat portion. Additionally, responsive to the haptic device vibrating at a third frequency, a third region of the chair may vibrate at a greater amplitude than the first region of the chair and the second region of the chair, where the third region is at a central portion of the seat portion between the front end portion and the rear end portion.

In some aspects, the second region is at the back portion. Further, the first region may be at a left side portion of the seat portion and the second region may be at a left side portion of the back portion. Optionally, the first region is at a left side portion of the seat portion and the second region is at a right side portion of the back portion. Optionally, the first region is at a left side portion of the seat portion and the second region is at a central portion of the back portion. Optionally, the first region is at a left side portion of the seat portion and the second region is at an upper end portion of the back portion. Optionally, the first region is at a left side portion of the seat portion and the second region is at a lower end portion of the back portion. Optionally, the first region is at a right side portion of the seat portion and the second region is at a left side portion of the back portion. Optionally, the first region is at a right side portion of the seat portion and the second region is at a right side portion of the back portion. Optionally, the first region is at a right side portion of the seat portion and the second region is at a central portion of the back portion. Optionally, the first region is at a right side portion of the seat portion and the second region is at an upper end portion of the back portion. Optionally, the first region is at a right side portion of the seat portion and the second region is at a lower end portion of the back portion. Optionally, the first region is at central portion of the seat portion and the second region is at a left side portion of the back portion. Optionally, the first region is at central portion of the seat portion and the second region is at a right side portion of the back portion. Optionally, the first region is at central portion of the seat portion and the second region is at a central portion of the back portion. Optionally, the first region is at a central portion of the seat portion and the second region is at an upper end portion of the back portion. Optionally, the first region is at central portion of the seat portion and the second region is at a lower end portion of the back portion. Optionally, the first region is at a front end portion of the seat portion and the second region is at a left side portion of the back portion. Optionally, the first region is at a front end portion of the seat portion and the second region is at a right side portion of the back portion. Optionally, the first region is at a front end portion of the seat portion and the second region is at a central portion of the back portion. Optionally, the first region is at a front end portion of the seat portion and the second region is at an upper end portion of the back portion. Optionally, the first region is at a front end portion of the seat portion and the second region is at a lower end portion of the back portion. Optionally, the first region is at a rear end portion of the seat portion and the second region is at a left side portion of the back portion. Optionally, the first region is at a rear end portion of the seat portion and the second region is at a right side portion of the back portion. Optionally, the first region is at a rear end portion of the seat portion and the second region is at a central portion of the back portion. Optionally, the first region is at a rear end portion of the seat portion and the second region is at an upper end portion of the back portion. Optionally, the first region is at a rear end portion of the seat portion and the second region is at a lower end portion of the back portion.

In some examples, the first region may be at the back portion. Further, the second region may be at the back portion and spaced from the first region. For example, the first region may be at a right side portion of the back portion and the second region may be at a left side portion of the back portion. Moreover, responsive to the haptic device vibrating at a third frequency, a third region of the chair may vibrate at a greater amplitude than the first region of the chair and the second region of the chair, where the third region is at a central portion of the back portion between the right side portion and the left side portion. Optionally, the first region may be at an upper end portion of the back portion and the second region may be at a lower end portion of the back portion. Further, responsive to the haptic device vibrating at a third frequency, a third region of the chair may vibrate at a greater amplitude than the first region of the chair and the second region of the chair, where the third region is at a central portion of the back portion between the upper end portion and the lower end portion.

In some implementations, a portion of the chair corresponding to the first region includes a first material and a portion of the chair corresponding to the second region includes a second material different than the first material. The first and second materials may include one or more of a plastic material, a metallic material, a rubber material and the like.

Optionally, a vibration element is disposed at a portion of the chair corresponding to at least one of the first region and the second region. The vibration element may include at least one of a plate, a pin, a tuning fork, a screw, a disc and the like. Moreover, the vibration element may be attached at the portion of the chair and/or at least partially embedded with the portion of the chair.

In some aspects, a recess may formed at a portion of the chair corresponding to at least one of the first region and the second region. In some examples, a portion of the chair corresponding to the first region has a first natural frequency and a portion of the chair corresponding to the second region has a second natural frequency different than the first natural frequency. For example, the first natural frequency may be greater than the second natural frequency by 20 Hertz or more, by 20 Hertz or less, by 10 Hertz or less, by 5 Hertz or less, by 3 Hertz or less, by 1 Hertz or less, and the like.

In some implementations, the haptic device includes a vibration element that attaches at the one of the seat portion and the back portion. The vibration element includes a first finger that extends between the haptic device and the first region of the chair and a second finger that extends between the haptic device and the second region of the chair. When the haptic device vibrates at the first frequency, vibration travels from the haptic device along the first finger to the first region to vibrate the first region of the chair. When the haptic device vibrates at the second frequency, vibration travels from the haptic device along the second finger to the second region to vibrate the second region of the chair.

According to another aspect, a method of manufacturing a chair includes providing a chair having a seat portion and a back portion. The method includes providing a haptic device attached at one of the seat portion and the back portion. Responsive to receiving an electronic input, the haptic device vibrates to impart vibration at one or more of the seat portion and the back portion. The method includes forming a first region of the chair to have a first natural frequency and forming a second region of the chair to have a second natural frequency different than the first natural frequency. The second region is spaced from the first region. The method includes determining a first frequency, where responsive to the haptic device vibrating at the first frequency, the first region of the chair vibrates at a greater amplitude than the second region of the chair. The method includes determining a second frequency different than the first frequency, where, responsive to the haptic device vibrating at the second frequency, the second region of the chair vibrates at a greater amplitude than the first region of the chair. This aspect may include one or more of the following optional features.

In some examples, the method further includes, based on the first frequency and the second frequency, determining a control function for the haptic device, where the control function includes a series of electronic inputs for the haptic device that cause the haptic device to impart vibration in a selected pattern or profile. The haptic may vibrate at frequencies between 1 Hertz and 40 Kilohertz. Optionally, the haptic device may vibrate at frequencies of 1 Hertz and lower and/or at frequencies of 40 Kilohertz and higher. Optionally, the first natural frequency may be greater than the second natural frequency by 20 Hertz or more, by 20 Hertz or less, by 10 Hertz or less, by 5 Hertz or less, by 3 Hertz or less, by 1 Hertz or less, and the like.

In some implementations, forming the first region of the chair to have the first natural frequency includes forming the first region of the chair with a first material and forming the second region of the chair to have the second natural frequency includes forming the second region of the chair with a second material different than the first material. The first material and the second material may include one or more of a plastic material, a metallic material, a rubber material, and the like.

In some aspects, forming the first region of the chair to have the first natural frequency includes forming the first region of the chair to have a first structure and forming the second region of the chair to have the second natural frequency includes forming the second region of the chair to have a second structure different than the first structure. For example, the first structure may include a first thickness and the second structure may include a second thickness greater than the first thickness. Optionally, the structure may include a recess or a protrusion formed at the corresponding region of the chair.

In some examples, forming the first region of the chair to have the first natural frequency includes forming the first region of the chair to have a first profile and forming the second region of the chair to have the second natural frequency includes forming the second region of the chair to have a second profile different than the first profile. For example, the first profile may include one of a planar surface, a curved surface, an angled surface and the like at the corresponding region of the chair.

Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the doctrine of equivalents.