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Creativity and style in music playing originates from constraints and imperfect interactions between instruments and players. Digital and robotic systems have so far been unable to capture this naturalistic playing. Whether as an additional tool for musicians, function restoration with prosthetics, or artificial intelligence-powered systems, the physical embodiment and interactions generated are critical for expression and connection with an audience. We introduce the parametric hand, which serves as a platform to explore the generation of diverse interactions for the stylistic playing of both pianos and guitars. The hand’s anatomical design and non-linear actuation are exploitable with simple kinematic modeling and synergistic actuation. This enables the modulation of two degrees of freedom for piano chord playing and guitar strumming with up to 6.6 times the variation in the signal amplitude. When only varying hand stiffness properties, we achieve capabilities similar to the variation exhibited in human strumming. Finally, we demonstrate the exploitability of behaviours with the rapid programming of posture and stiffness for sequential instrument playing, including guitar pick grasping. In summary, we highlight the utility of embodied intelligence in musical instrument playing through interactive behavioural diversity, as well as the ability to exploit behaviours over this diversity through designed behavioural robustness and synergistic actuation.

Abstract Additive manufacturing, or 3D printing attracts growing attention as a promising method for creating functionally graded materials. Fused deposition modeling (FDM) is widely available, but due to its simple process, creating spatial gradation of diverse properties using FDM is challenging. Here, we present a 3D printed digital material filament that is structured towards 3D printing of functional gradients, utilizing only a readily available FDM printer and filaments. The DM filament consists of multiple base materials combined with specific concentrations and distributions, which are FDM printed. When the DM filament is supplied to the same printer, its constituent materials are homogeneously blended during extrusion, resulting in the desired properties in the final structure. This enables spatial programming of material properties in extreme variations, including mechanical strength, electrical conductivity, and color, which are otherwise impossible to achieve with traditional FDMs. Our approach can be readily adopted to any standard FDM printer, enabling low-cost production of functional gradients.

This paper proposes a low-power design method and a low-noise phase offset calibration technique for a gated ring-oscillator time-to-digital converter (GRO-TDC), which normally consumes a large percentage of most all-digital phase-locked loop (ADPLL) power. A single coarse counter logic structure along with time-interleaved even/odd paths significantly reduces the complexity and speed of the TDC logic. The proposed TDC consumes only 0.44 to 24 mW for 0.077 to 24.42 ns of detection range. The multi-path GRO accelerates the oscillation speed and achieves approximately 6.2 ps of time resolution. The GRO-TDC shows –1.43 to 1.35 least-significant bits (LSB) of differential non-linearity (DNL) and –1.32 to 1.96 LSB of integral non-linearity (INL) over a 11-bit dynamic range (DR). The entire ADPLL including the proposed TDC has been fabricated in a 65 nm CMOS process and occupies 0.67 mm2 of active area. The prototype ADPLL consumes 12.22 mW from 1.2 V supply and the TDC consumes only 0.65 mW for a 50-phase offset code. A modified integrating structure in the subsequent digital loop filter (DLF) has been developed to mitigate dithering noise on $V_{ctrl}$ code and the measured reference spur is –69.38 dBc at 3.6 GHz center frequency. The tuning range of the implemented ADPLL is 3.5 to 4.7 GHz by using 2-bit band switching and 5-bit coarse control, while maintaining low- $K_{DCO}$ values to suppress in-band quantization noise. The measured root-mean-square (RMS) jitter is 0.94 ps and 0.99 ps at 3.6 GHz integer-mode and 3.60743 GHz fractional-mode respectively.

This paper presents a Ka-band beam steering transmitter exploiting a coupled varactor loaded transmission line (VLTL) phase shifter and a CMOS transmitter chip with an integrated frequency multiplier. The short-coupled line couplers placed along a single VLTL provides multi-phase outputs while minimizing the impedance mismatch and unequal power distribution along the VLTLs. The inherent phase-accumulating nature along the VLTL reduces the burden of wide phase control range required for using separate phase shifters for each channel. Additionally, the frequency multiplier with a multiplication ratio of 8 reduces the required amount of phase change at the reference frequency and therefore the tuning range of the varactor, which also minimize a change of line characteristic impedance to ensure the impedance matching of the VLTL. Hence, a 32 GHz phased array transmitter is implemented using a single VLTL phase shifter operating at a low reference frequency of about 4 GHz. The fabricated $1\times 4$ phased array transmitter achieves a continuous beam steering range of ±20° in the E-plane using a single control voltage. The sidelobe level is below -10 dB at all scan angles and the peak effective isotropic radiated power (EIRP) is 38.1 dBm at 31.6 GHz and the 3-dB bandwidth of 2.4 GHz is achieved.